The Symfony community has been going for Server Sent Events rather than websockets, via https://mercure.rocks/. I don't understand the benefit when every other framework wanting interactivity is still going for websockets.

As you say SSE seem more suitable for notifications rather than bi-directional communication.

I hope too HTML Over the Wire will be trending, I hate all the SPA and JS madness nowadays.

SPA/React/Flutter are great tools and technologies, when you have a team for the backend and one for the front end. If you are a little startup or a single man project, that’s quite huge to maintain