The good bits are also very short lived. Basically once you get all items you need for a build it's fun for an hour, but from then you only get marginal improve

The good bits are also very short lived. Basically once you get all items you need for a build it's fun for an hour, but from then you only get marginal improvements in grinding to get even better versions of the same items. For me that's when i get bored and lose interest. The problem with D3 is that you can skip pretty much all the boring prep and just hit max. lvl in minutes and then play a couple hours to get the needed items.