Railway/Render can easily host Next.js applications

You could also get a VPS from Digital Ocean or Hertzner, run open-source PaaS like Coolify, Dokploy, Caprover, etc.

Digital Ocean has app platform that’s lets you host these applications but more experience than VPS

Sealos has a $7 and $25 plan and work with Next.js

Just a few options. If you’re looking to leave Next.js completely, check out Tanstack Start. It’s by the creator of React-Query (defacto way to handle fetching data in Next.js). Still some rough edges but I think it could overtake Next.js once a bit more mature.