Chaney's offense fit Fromm really well. Not sure exactly how different the UGA playcalling is this year compared to last, but that was the biggest change between this year and last year.
The play calling was fairly similar. It was worse because Coley is an absolute idiot, but it was very much the same scheme. Kirby Smart is in love with the conservative, run heavy scheme and insists his OC's use it.
The biggest difference for Fromm was the fact that he lost 4 weapons in the receiving game to the NFL. The replacements were much more pedestrian. That being said, it's not like UGA's receivers were bad, they just weren't studs constantly getting open by 5 yards.
Fromm really struggles in knowing when a receiver is about to come free and throwing the receiver open. He needs to actually see the receiver come open. This leads him to giving up on receivers too early and not seeing them come open, it leads to defenses having time to react and close the distance when guys do get open, and it leads to Fromm checking down an awful lot.
When he could rely one a couple guys being wide open every play, it was easy. When those guys left and it was up to Fromm to have to know when receivers would get open and throw them open, he failed.
Fromm often gets lauded for not throwing many picks, but that's more a result of him not taking many risks. If he doesn't see a guy wide open, he checks down and dumps the ball off. It leads to a very unproductive passing game.