Is not about changing, is about adding. Add something new, develop the story a little further, put more cutscenes, make the station bigger, put new sections in.
FFVII managed to do a 40 hour game of what was 4 to 5 hours of the original.
I can finish RE2 on PS 1 and RE2 remake in the same amount of time. That tells you a lot about how much work were out into this remake.
You're saying that the reboot of FFVII is better or worse?
Serious question. I mean, take 5 hours of an amazing game and change it to 40 hours, you have to add a lot of unnecessary fat to it.
If they manage to make all like the original, at least we could have a complete product for U$60. Now, instead, anyone who want to play the full game will pay on the best case scenario: U$180, on the worst, U$200...
The best thing about RE2r is how it really makes you remember how good the original was.
Now, talking about FFVII, the new one is so boring that even "for free" at PS+, I tried to play it, but I couldn't. That is way too different and aside of being a hack'n'slash with FF skins, it just don't remember me of anything that makes the original so special.
Meanwhile, RE2r can do that, despite changing the camera scheme, they managed to make this game feels like the original RE2(I don't know anything about game development, but I guess that this is really, really hard to achieve).