I can't tell you how many snappy, easy-to-use React sites I've used (I was busy using them, not reviewing their code), but every single time I've said "What the hell is going on, I'm just trying to [simple operation which is the only purpose of the website I'm on]" in the last five or so years, it's some React/Angular/SPAFrankenstein monstrosity.

I could say the same about almost every web app that gets rendered on the server because every tiny step of interaction needs a network round-trip.