IMO the main problem actually lies with the design team.
For some reason or another, Mihoyo's character design team have literally been pumping out characters who fill the exact same niches over and over.
As a result, of course there's going to be people angry that the new 5-star they spent money for is getting outcompeted in the same niche by a 4-star everyone already owns.
Similarly, of course there's going to be people getting angry that the new 5-star they want (Yoimiya) is looking to be worse than an existing 5-star who fills that exact same niche (Hu Tao). (And the vice versa is true as well: Hu Tao and Ganyu owners will, consciously or unconsciously, be angry and defensive if a new 5-star is released that overtakes their characters' position at the top of the meta.)
We wouldn't be constantly so scared of powercreep if Mihoyo was actually willing to diversify their new characters beyond just the exact same archetypes of "pyro main dps" "cryo main dps" "anemo swirl support."