To be quite honest, I think the FF7 remake trilogy is just a really bizarre project anyway, business wise.
From what I can find, the first game apparently started full production in late 2015 and released early 2020. Rebirth released about 4 years later. Assuming the 3rd game takes the same time, this entire project would have taken ~12.5 years.
Spending 12.5 years to remake a single game as 3 separate games, where from the outset it's basically clear that each game will have a lower sales ceiling than the last (because that's what usually happens with direct sequels) and then not even trying to maximize that initial ceiling but instead going exclusive to a single platform again.
And then it's apparently not even a straight-up remake, but instead does new story stuff/changes(?) that works best if you've played the original 27 year old game, so you're inherently also focusing more on an older audience instead of inviting a new generation of players.
And then they are not even on the same platforms. Remake is a PS4 game, with a PS5 only DLC and Rebirth is PS5-only.