I'll chime in and say that I did the same. A lot of people like Fly but I wanted super low complexity. My hope has mostly panned out. I was able to move without too much difficulty and I'm happy with how it turned out.
I’ve found render the closest to heroku. I was able to setup a service for my rails app, for Postgres and for sidekick.
Not as polished as heroku or maybe fly but like I said they made up for any gaps from the bend over backwards live chat support.