I've been using DigitalOcean App Platform for a while now. It's not a 1:1 Heroku replacement, but the git-based deploys, managed DBs, and ability to move to Droplets later without a big migration have worked very well for me.
Digital Ocean App Platform is great. We switched to it from Heroku in 2021. It had some growing pains to start, but has been rock solid since. I can only think of 1 downtime incident that was their fault. They continue to improve the platform too, and are VERY responsive to requests.
Yeah, I moved a while back to DO's App Platform. I've not had any issues with them so far. Recommend them a lot.
I am considering DO App Platform for a new project. Would you be open to sharing any lessons learned ?