Leveling is an expected part of the ARPG experience, and it comes before the endgame. When it comes to the endgame itself, I don't mind some friction, but it's important where that friction is placed. If I just want to log on and mindlessly kill monsters for a couple of hours, there shouldn't be anything discouraging me from just turning my brain off and doing that. Diablo 4 feels like it places obstacles between players and the main activity of the game.
An example of friction done well is PoE. Crafting and trading are both time consuming and sometimes tedious experiences, but blasting maps is always just a click away.
League starters and QoL often do not go hand in hand, so it's not something I worry about very much when a new league starts. I've only ever dropped one build due to shitty QoL, and that was Maw of Madness Elementalist in 3.20.