So, like with most games, I don't think that the core of
FFVII itself has a story that really lends itself into a film format.
The reasons that film adaptations of games & books end up being different is just because of the nature of how storytelling works for those two mediums. This is also why a lot more adaptations of books & games are shifting over to streaming where you have the time & bandwidth to be able to develop those sorts of narratives with the space that they require to actually be told, and also where the length of each episode can vary just like the length of a chapter of a book / game.
I wouldn't expect SE to make any sort of
FFVII live-action Hollywood film unless the ROI & interconnection to a huge Western audience that Kojima makes on his upcoming
Death Stranding film is just off-the-charts to the point that it would be crazy for them NOT to do it. Given the way that SE operates financially at the moment, I really don't expect that to happen unless what Kojima does just shifts the needle to a massive degree that's impossible to ignore – which I really just don't see happening. Even if that
IS an overall success, I don't think that the exposure that it'll generate for the
Death Stranding IP will be much different than just having Norman Reedus and others in it – like it already does.
To that point, I honestly think that the closest thing that you'd ever get would be something along the lines of
FFXV: Kingsglaive where the story happening is something that's adjacent to the events of the game & there are big name actors in it doing VA, but everything's still created digitally – which really just puts you in the same territory as
Advent Children but also narratively in what they've been exploring in
Ever Crisis with
The First SOLDIER. Those sorts of brand new narratives can naturally shape themselves around the constraints of the format of the storytelling of film without compromising anything that they would otherwise by being an adaptation of a larger story that was designed for a different medium (which'll be what's interesting to see in how
Death Stranding is doing as its approach strategically for its film release and what exactly the film decides to focus on).
If anything, I think that when it comes to
FFVII and its setting,
Ever Crisis generally opens up the ways in which side-stories might be told with things that interconnect into the
FFVII world itself where
SOMETHING in live-action isn't out of the question, but like
@Eerie mentioned, I think that the biggest potential that the
Remake Project has opened up overall is that Part 3 could deliver things into a post-
DoC setting where it's FAR more possible to set up for others to tell other stories in that world as a setting that don't bump into things from the game itself too egregiously. I still think that things like when the Cetra first fought against Jenova, as well as the post-Omega conflict world have decent potential for interesting stories, games, novels, films, animations, etc. to be told about them.
However, if you
REALLY want SE to go that route – be careful what you wish for on that monkey's paw...
because there is already a live-action FFVII Compilation character whose story is literally set to kick off the post-DoC world 
TBH: I personally have zero problems with this but I'm not sure that everyone would be on board. Gackt is in his early 50s now and he's still touring, so I figure that the clock for that to ever happen is a fairly limited window one way or another. However, Gackt's history as Genesis in the original
Compilation titles as well as in
Crisis Core Reunion bring us to a couple other important factors to consider about creating something in live action.
One of your main motivators around this is the impact that live actions brings in pulling in mainstream audience, but I'd argue that what you're actually looking for is something from Hollywood, since despite Gackt being live action and having
ENORMOUS star potential & name recognition when it comes to the core Japanese audience –
that would do literally nothing insofar as having a "mainstream impact" anywhere outside of that market. Live action film that comes out of Japan generally needs to have the reach of something like
Godzilla Minus One to really register on the map at ALL in the way that you're talking about, and even then the overall reach is still not that significant beyond the already notable venn diagram of overlap between people who are fans of both sci-fi/fantasy and video games... – hence bringing everything back to whatever the outcome of
Death Stranding venture looks like when that potentially drops in something like 2027 assuming that all goes smoothly.
However, even beyond that – the biggest complication that anything live action presents is for character dubbing. Not only was Gackt's dub one that has shifted English VAs and whose live action appearance was... rather polarizing to put it mildly – one of the biggest technological pushes that was made during the early development of
Remake is what allowed them to dynamically adjust each character's speech & facial expressions to automatically match to the VA's performance in ANY of the languages that are available for the game, such that the characters' mouths & expressions BOTH match that of the spoken language.
This is MASSIVE when it comes to the emotional moments connecting with a more broad international audience, especially when you're looking at any "mainstream" impact (especially because the core mainstream Americans are known for being allergic to subtitles). On top of that technological hurdle in live action being something that they don't need to deal with by keeping it in the realm of digital realism that the
Remake Project focused on for its overall stylization, there's also already a massive marketing investment into the characters current English voice actors who were brought on for
Remake. It's pretty much impossible to attempt to focus a film on a story around the original game without undercutting a huge effort just to gain a foothold with a primarily Western audience that doesn't just create a disconnect to the existing fanbase, but especially since a big Western film won't necessarily translate to a wider impact within the core JP audience in a way that would make that financially incentivized for a company like SE to attempt as an undertaking.
Essentially, as much of a deeply internationally loved story as
FFVII is, at it's core it's still very much part of a company where a vast majority of the ancillary material is still primarily focused on the JP audience (ex: despite everything else I've mentioned thus far,
Ever Crisis has no options for English dialogue). I don't think that there's any way that
Final Fantasy VII branches out into making a colossal financial risk of releasing a live-action adaptation, but ESPECIALLY since the success of
FFVII and the gap in understanding the difference to game & film development
is LITERALLY what lead to the fumble with FF: The Spirits Within, which everyone close to that team knows all too well.
Basically there's almost no way you'd ever get an official live-action film adaptation of
FFVII in any way that I can think of. If you get
anything live-action that's connected to
FFVII – it's almost certainly going to be a JP-audience-centric spinoff content that is primarily involving Gackt and which takes place after the
Remake Project wraps up the main story with Part 3, and opens up looking at whatever possibilities that world has to offer in the wake of that conclusion.
X 
