For me, the crux of the issue are the monsters.
In Diablo 2, you never knew when you would find a unique, a 6-socket etherual weapon, a good rune, a set item, etc… People didn’t just farm the bosses. World stone keep, some of the caves (The Pit), the cow level. In any of those places, you could find rare items better than unique itmes, set items, runes, or even uniques.
The monsters were the slot machine. They were not in the way of you getting your loot, they were the loot. That is why I also went back to D2R before the season started. I jumped on my sorceress. I didn’t know which one because I had 4. All different. This one was blizzard/hydra. I went to run Worldstone Keep and I was running past the monsters to Baal when it hit me…they have loot!! I had been playing D4 where monsters were not going to drop anything good.
One of the core problems with D4 is the designers want to reward you for completing an event, or a dungeon. They made the monsters in the game an obstacle between you and loot. What you do in Diablo 2 is get rewarded for killing the enemies. There is no end point where you get the loot. Sure, bosses in D2 have a better chance of dropping good items, but the rest of the mobs are not just an obstacle.
In D4, monsters are an obstacle. I run past them. I don’t touch treasure chests or shrines in dungeons because I will get more obstacles that spawn for at least a minute.
What D4 has done, is watered down the loot pool and increased the drop rate significantly. You have to spend time looking at every item in your inventory to see if the 1/10,000 or more chance of an item being useful gives you a marginal upgrade.
What you do 99% of the time in D4, killing enemies, is not what is rewarding. The reward is always at the end of what you do 99% of the time. More often that not, it is just as useless.
This is why I continue to play D2. I can spend 10 minutes or 4 hours. There isn’t anything like hell tides where I have to play a certain amount of time to get good loot.
I like hell tides because the monsters drop something useful, cinders. That is the best part of the game to me. Everything you kill will more often than not drop something you can and will use. They are not longer the obstacle, but the reward.