OG FFVII is full of minigames. I don’t think rebirth has more than the OG, also it’s like half of the game not a third (the last disc is just the final dungeon, and the second disc is not as long as the first).

When the OG does a minigame it’s often a one and done thing. Rebirth madness it fell like more because you can go back and do more of each minigame with increasing difficulties etc.

I think subsystems just lend very well to JRPGs because they’re often trying to create a world, and adding such to their games makes their worlds feel more full. I also think the Japanese do their game development different to the west most of the time. Since a lot of these minigames are made because developers have finished the parts of the main game they were working on so they mess around trying to make something new and fun that might be able to be tacked on as an extra.