Heroku is the Vercel of Rails: people will pay a fortune for it simply because it works. This has always been their business model, so it’s not really a new development. There’s little competition since the demand isn’t explosive and the margin is thin, so you end up with stagnation
You'd be surprised. There are very few because it takes a lot more work to build reliable systems across mid-market cloud providers (flakey APIs, missing functionality, etc). Plus you need to know the idiosyncrasies of all the various frameworks + build systems.
That said, they are emerging. I'm actually working on a drop-in Vercel competitor at https://www.sherpa.sh. We're 70% lower cost by running on EU based CDN and dedicated servers (Hetzner, etc). But we had to build the relationships to solve all the above challenges first.
