Square Enix says it remastered Chrono Cross so it wouldn't become an "unplayable" game
During an interview with Square Enix, producer Koichiro Sakamoto revealed that the recent Chrono Cross: The Radical Dreamers remaster wasn't just created to celebrate the original game's 20th anniversary, but to also ensure that Chrono Cross would remain playable for fans. Sakamoto stated that as a PlayStation 1 disc, Chrono Cross was available on the PS2 and PS3 through backwards compatibility, but there were fears from Square Enix that with the lack of PS1 support on the PlayStation 4, the game would become "unplayable" entirely.
Back when the project was launched, Chrono Cross was possibly going to become unplayable. There was a Game Archive service on PlayStation 3 that allowed you to play PlayStation 1 games. But PlayStation 4 was already on the market. We didn't know at the time if PlayStation 4 would also have a Game Archive service. It looked like Chrono Cross could become unplayable. So, a remaster project was set up. That's the backstory.
Ironically, Chrono Cross's remaster was rife with bugs and framerate inconsistencies, making the game quite unplayable for some on the PS4. Only just recently did the game get a patch that promised to fix many of the issues players had with the remaster at launch.