Blizzard is adapting to a new market, new players. Myself included by the way.
They could prune everything to the bare minimum, like in Darktide where the game is literally 3 buttons.
But then the content would have to be the challenge. With more swirlies, and would require more reaction time.
So be careful what you wish for. 
Nah. I agree with those “streamers”.
Random stuff is OK. But not if its OP powerful like it was in BFA.
Think of walking into an arena, and 10% of the time you get 1-shot by someone because he got a lucky proc. Not fun. For both players, because for him, 90% of the time he will get mauled.
It happens today in M+ with DK. If blood beast procs then the pack melts. If it dosent, the risk of wiping is 50/50 cause its like playing with 2 DDs.
And then Passive Effects are boring as hell. Plus, 50% of the talent trees are passive. So they kept that functionality, nothing to complain here.
Some not enough IMO. Here is my opinion:
Classes have to be designed in a way that there is a basic gameplay that allows you to clear the whole content. Problem is, you got people of different skill levels that demand different things. And class design is supposed to accommodate for all of them.
For example: Take your 20 keybinds. Simply remove 15 of them from the bar and only use 5. How much performance drop would that be? For most specs, were talking like 30/40% performance drop?
Well now the question is: Can you do a +2 using only 5 buttons? YES. For 99% of specs.
The rest of the buttons simply add depth. So between a +2 with 5 buttons, and a +18 using all 30 keybinds at 300 APM there is a range. And within that range people with different skill levels have to fit.
I am very passionate about healer DPS, and that is a prime example of what I mean with this philosophy. Can you do “low level” (+2 to +14) dungeons with ZERO dps talents, and with out pressing a single DPS spell? You absolutely can and you will be successful.
But if you want to take your spec further, for “fun” you can optimize healer DPS with more spells and talents. And that gives extra “fun”.
Shamans dont have button bloat. That’s ridiculous.
You assume that having 10, 1 or 2 minute CD totems implies that I have to use them all the time, OR that I even have to key bind them.
You dont have to keybind everything, you can leave some things as “click” (old school). And you dont have to use everything all the time on CD for every pack.
So we technically have 30 buttons. But realistically, we are only using 4 or 5. The rest are very situational.
In any given fight, I use 6 spells all the time (Riptide, HS, HW, CH, CB totem, HR). And maybe 1 or 2 totems more that I use once or twice in a 5 minute boss fight. The rest of the stuff remains unused for that particular fight.