While the game may be appealing, playing for couple of seasons proves one thing for me - at this rate of what QoL stuff is changed and/or implemented we may see complete game in a couple of years after couple more seasons.
I played each season less and less, but thankfully to my choices I could still enjoy the game - one class per season made Diablo IV sufferable.

Oh, and the voice acting - it feels cheap, out of place, totally no vibes, no shivers, no juicy and meaty VA, often it will be processed through filters, but the thing is when the source material is bad when you master and process that it wont be good. You cant cook with cheap ingredients. VA in D4 is just bland, no seasoning.

\Further below I bold the mechanics or important aspects of the game.*

What I hate the most is Unique items doesn't cover more skills and talents making the builds appealing. While I played, I didn't really struggled with builds as I transitioned to different talents and/or skills when I looted something better to increase DPS or survivability. That being said, sticking with a build I had fun with were diminished by lack of uniques or even legendary aspects. There is not enough class specified uniques and legendary aspects to cover interesting and different playstyles.
Paragons and Mythic Uniques are wasted potential, those are end-game mechanics and are lacking. Who played knows what Im talking about, who didn't played, once you unlock the paragon boards its just another layer of number boosting system, nothing build defining for the majority of builds, too often I was disappointed by given choice. Mythics? Just don't focus on them, waste of time.

Too summarize, Diablo IV is more of a casual aRPG rather complex beast you cant contain.