Mastodon runs as a rails api with a react frontend. Last time I discussed this people mentioned it was the worst of both worlds and I get the argument.

But doing things that way means nearly every fronted dev can work with their favourite patterns and frameworks. I love that they can debate replacing create-react-app and i do not have to care beyond saying "as long you meet the openapi spec". Moreover, everything you've described along with most of what has changed recently in the ecosystem goes away. I don't have to care what is happening to hotwire, or the asset pipeline in general or around scss gems being deprecated.