I feel like there’s plenty of class fantasy at play. Each class plays quite differently and requires you to rethink about each fight/encounter when you switch classes.
At least it does with the healing/dps roles.
Across tanks not as unique because how you play is more driven by the boss and trash - not so much your abilities.
But personally I’ve always felt that the fantasy and immersion has been great across classes and within a single class.
If they give us the ability to switch covenant abilities freely (like talents) then they won’t have to worry about balance.
Players can just choose what they want based on what they’re about to do.
This may seem like a weird suggestion but…
Why not just make the abilities all do an average of 150 dps for mages. Then you pick your covenant on flavor and design.
They are using an “autocorrecting” mechanism to entice Alliance to War Mode and it isn’t really the solution that people thought it would be.
Class fantasy is in no way gone. They’ve just combined the skill of the player with all that the class has to offer.
A good player that knows what talents to pick for which dungeon or raid boss is way more valuable and an effective class - than someone who just picks one set of talents for everything they do.
The latter is boring and doesn’t provide the player to make decisions that have an impact on the game for their team. The former does that and allows a good player to shine by letting them make full use of their class.
I can’t believe that there are people here suggesting talents should be permanent and never be changed. I don’t play many alts so I don’t know what it’s like for every class, but I’m constantly changes talents, essences, and azerite traits around to suit what I’m doing. My WQ build would be trash in raids, and my raid build would be trash in m+. That’s good design. A one size fits all set of talents is boring af.
Some people are a mix of sadists and people with tons of time.
They either play casually where optimizing doesn’t matter to them, and they enjoy seeing the more competitive players suffer.
And/or
They have tons of time and level up multiple characters of the same class to suit all the roles. Which is antiquated - but hey, when they have time to burn, I guess why not?
Exactly!!! They don’t care of try hards
They know they will make another alt to farm the cosmetics to get more time metrics out of them .
Grind baby grind. 
lets be honest here… i’d wager most people will go into shadowlands, check raidbots, icyveins, w/e is the current site simming these abilities and pick the covenant with the better numbers.
i don’t understand the point of adding something like this with a ‘choice’ and a high cost to change when mostly everyone just looks at a sim site and picks the best option
its the same issue with azerite, a high cost to swapping just deters people from experimenting with builds and play styles, and makes them feel that their best option is to pick what sims better on a webpage.
these abilities really should’ve just been lvl 60 talents.