Pretty different approach, but with many application architectures today you can move beyond "hosting" into pure serverless with a stack like Vercel + Convex (https://convex.dev)
Preface: I work for DevGraph, which contains EngineYard.
I would definitely have a strong look at EngineYard [1]. Our tagline: "A NoOps PaaS for deploying and managing applications on AWS backed with a world-class support offering." There is a good comparison with Heroku located here [2].
Having worked with several engineers, I can personally vouch for the world class support. We spend a lot of time thinking about and implementing ways to host Ruby, Node, PHP, Java, Python, and other containerized workloads on AWS. EngineYard has been around since before Heroku, so we have a long track record and a lot of experience in making your applications run reliably, keeping costs under control, and with full 24x7 support.
Email is in the description, along with my Twitter. Please reach out for any questions.
https://www.cloud66.com/ if you want support for all major cloud providers including bare metal ones, native support for MySQL, Postgres, Redis, Elastic, memcachD and tons of features for your entire team
https://railway.app/ is really good. Easiest way to get a project up and running IMO. You can deploy from existing GitHub repos or a project starter in one click.
Dokku also supports Dockerfiles, Docker Images, Tarballs (similar to heroku slugs), and Cloud Native Buildpacks. I'm also actively working on AWS Lambda support[1] (both for simple usage without much config as well as SAM-based usage) and investigating Replicate's Cog[2] and Railways Nixpacks[3] functionalities for building apps.
There are quite a few options in the OSS space (as well as Commercial offerings from new startups and popular incumbents). It's an interesting space to be in, and its always fun to see how new offerings innovate on existing solutions.