I think you meant gen 3.5.
If even that, as a bunch of things are a downgrade from gen 3.
Split was done in the worst way possible (lol Draco Meteor/Outrage meta)
Stealth Rock ruined singles forever
Slow ass battles, text, menus
Saving a lot of data
Frontier is a direct downgrade from Emerald
Super contests aren't even an improvement over contests
No breeding improvements
Even more trade + hold item evolutions
Sinnoh's dex is a fucking mess