However the character build system is basically the same as D2 in terms of raw customization. Every class uses one of a few builds which are the best as well as some themed builds which are fun but not that great, each class has a few specific legendary (unique) items that they want, each class has one or two specific stat builds to aim for, it's really the same thing.
People who think D2 had great class customization are wearing rose tinted glasses in my opinion. Every single class outside of outlier builds (aka, builds not as good as the general builds. Fun maybe, but not as good) had the exact same stat build: Str for gear, Dex for gear or max block, rest into vit, nothing into energy. Every class had a few popular builds that were the best and some fun/weird builds that could work but were never top tier, each class had a few unique items that made them overpowered...sounds familiar doesn't it?
Every ARPG out there is basically cookie cutter or bust, always has been and always will be. Even the touted orb system from PoE has very little actual customization if you want to do the hardest end-game stuff solo. In any game about stats there will always be the kings, the hope is that the queens are just as fun as the kings. They never are though, being the best is fun, being able to wreck things you aren't supposed to do solo is fun, even grouping in an ARPG can be fun (of course you get kicked if you're a queen build and not a king, so...back to king with you).