a developr can limit the power of user-agency by moving increasing amounts of power to the server.
this trend amplifies developers potential. and it allows targetting "dumber" web clients. yay, good things. but it also makes the most advanced & competent web users less able & less capable. web apps have, for a while now, been fairly client-heavy, in a way that enables hacking & creativity. i'd love a strong counter-thesis for why this isn't the case, but this feels like a mainframization of computing, a push towards centralized control. it has upsides, as you point out, but also it keeps much more reserved & controlled & hidden. that is not very "web" like, tbh.