Biggest thinga are IMO save/load for online games and also a rollback of the campaign changes from 1.33.
Though, thinking about the latter: Fucking hell, Blizzard. Fucking. Hell. It should never have come to a situation such as this in the first place!
The three biggest (note, not only ) points
-It was patched over previous versions. You can’t play the non-reforged version anymore
-It removed features the previous version had. In particular networking
-It released with desync issues that would randomly drop players from the game. Wc3 doesn’t support rejoin so this basically killed maps depending on how severely they were affected (and note, it even affected normal maps. But custom maps suffered tremendously from this)
Like just given those three points: Why don’t you understand?
The fact you even say that custom games improved just makes me think you’re being dishonest for some reason…because it wasn’t some secret or even rare occurrence. 90% of custom maps were suffering it.