Why I can't enjoy POE 2

Yesterday, I just finished Act 3, and sadly, I can't say I enjoyed it. Today, I came back home and didn't even want to play anymore. In my opinion, the gameplay is way too slow and not rewarding enough. Enemies have way too much HP and deal low-none damage. Small enemies that you'd expect to kill in one shot, like the spiders or mosquitoes in Act 2, take far too long to die.
When I entered the harder version of Act 1, after about 3-4 locations, I turned off the game because I was so bored. I had no intension to slowly get through every map only to kill all the Act bosses again that die in comparison way too fast. I really want to enjoy this game, but clearing maps feels way too slow and painful because maps are way too huge and enemies just refuse to die quick enough. It’s just about making your way through tanky, non-threatening enemies it gets very boring very quick.

And don't even get me started on the loot. I know I’m only in Act 3, but still—when I kill a rare monster that took me more dan 20 sec to kill, I expect something better than a few white items, maybe a magic item, and a little bit of gold.

Another issue is the Ascendancy trials. In PoE 1, the Labyrinths were maybe a little boring, but at least they were fair for every class. Now, the first trial is in the Sanctum, where glass cannon builds have a huge advantage, while tanky regen-based builds are nearly impossible to do. I shouldn't have to respec my character just to make it through the first trial. I don’t mind the Sanctum itself it’s just that in PoE 1, you had to be ranged to do the Sanctum efficiently, but now it's a necessity, which seems unfair to tanky builds that lack high damage.

Before someone tells me, I had jus a bad build, I’ll point out that I had 10-15k DPS at the end of Act 3, and 70% of my damage is splash, so I shouldn’t be having trouble clear speed when bosses are taking 20-90 seconds to die. And please don’t write skill issue be more creative.
I love to hear your opinions.