Imo Rails is currently the fastets most conevenient framework to develop in because of its comprehensiveness and maturity. But what I'm looking for is something more radical [copying my comment below] where the frontend and the backend is more integrated. The way it's done now data structures are duplicated. Of course this has to do with how things are done with REST over HTTP. Meteor actually implemented their own websocket protocol -- it's ideas like that I'm looking for.
Of course you risk making monoliths with this approach, but like I said I'm primarily looking for something that makes it easy for solo developers or small teams.
I built a huge SPA application that is real-time connected by web sockets (Turbolinks which is included in Rails) with Rails. I did it in 3 months, alone. Hired our first engineer and we can tackle pretty much anything that comes up. I think Rails has worked incredibly well for a small team. The addition of webpacker allowed us to use React where it makes sense and Rails views everywhere else while Turbolinks holds it all together. Rails is the framework you describe.
You don’t really duplicate that much between server and client. Yes, you have models on both. But the models do different things. Server is all about validation and querying a database to generate responses. Client side is all about user interaction.
