(More spoilers for other ppl)
Yeah you have a point too i think, they were in a loop and if they could change something in each reset then Zero would have not returned their memories i guess, also that the MC(or idk if his name is ben afleck or alex according to the other games) likes to take an "observer" position rather than being a leader or having an important role most of the time.
I liked the Carmine-MC relationship in the other games(not counting "butterfly" game lol, but still i think she was forced to do those things) so there my bias toward Carmine, and they had its funny moments, if i saw development in CC-MC(but i think CC talks to the player, ddlc vibes) i would say it's a tie between those relationships.
I like Mirall, but idk, i feel sometimes that MC would only use Carmine so Mirall is born, or he is just "dense" as Carmine said. Also mainly focused on the MC romantic interests, but loved their Father and daughter relationship
Also I liked a redhead girl in high school(natural tho), at some point we were getting close but i didn't try or do anything then, now she is in another country, and Carmine did remember me her *sob. Now i know i'm into redheads completely lol.