It is only my impression, but it is a mix of different factors, and it really started after the HoloFES 2 when they announced Bloom. At that time, Cover publicly declared that them and the holos both wanted to take their idol career to the next level, which in itself is a positive thing.
The issue is that at the same time, they sorta tried to be more mainstream , marketable or advertisement-friendly and they started to have more restrictions on what they can say on stream, the games they play, the persons they can mention or collab with compared to before. In general, you kind of feel that it has been sanitized and that the talents begin to become generic (like gacha) even if this is not the case when you know them.
Also, at first, but it is better now, they took dance and singing courses that visibly affected how much they streamed for weeks, the most recent example with the 1st gen holos.
Finally, I am not a big fan of how merchs became more and more pricey, and how most of the newly released songs lack personality, but it is more a matter of taste in that case,
All in all, what I wrote also already apply a bit to Holostars anyways. I want to believe it will be fine since there aren't a lot of members in Holostars, and that they shouldn't get that much attention compared to all the other branches, but I can't help having mixed feelings. It is the classical case of wanting things to keep the same scale, but wishing it is kind of egoistic if Stars want to grow more.