Your idea to update one of the easiest, most straightforward, and repetitive battle systems is to add visual flair? And that is "modernized"? Do you work for Ubisoft or something?
The original game is brain dead easy, there is no strategy. There are less than 10 battles in a 60 hour game that requires thinking (and some of them are optional). This is not enough to warrant an ATB/Turn-based system, a system that relies completely on strategies and customization to be fun. But hey, at least you are the one ordering everyone to do nothing but attack instead of the AI, right?
The problem with the original is not that it has an ATB battle system, the problem is that the game is not fun to play. It takes dozens of hours to find any challenge, they are rare, few and far between, and not worth the slog that all the other battles are.
Random battles don't need to be hard, but they should require more than attacking nonstop.
Bosses should require a deeper strategy than "don't attack when it's tail is up".
Customization in that game is great, yet all it does is leave you overpowered for the endgame (that is also easy).
I love FFVII and wouldn't mind either battle system, but if they are going to keep the game as easy as the original, then at least make it action so it's more fun to mash...