What do you mean? There's so many Heroku competitors these days that the perception has changed towards Heroku being a relic of "how it used to be done". Competitors like Vercel don't just do what Heroku does, they do everything better. (And now edge-first ideas like fly.io are catching on)
Another start-up I've been playing with is Railway, who offers 5-10$ of free usage per month, certainly enough to play with react/nextjs app and a postgres db to your hobbyists hearts content (as long as you turn if off when you're done).
I mean Vercel has a lamdba/serverless feature but you can absolutely point a git repo at it and have it build your site and run your node backend. It's a little more abstracted away, but then again Heroku is just an abstraction on Aws, and the newer era of tools are a bit more abstract than Heroku.
Another start-up I've been playing with is Railway, who offers 5-10$ of free usage per month, certainly enough to play with react/nextjs app and a postgres db to your hobbyists hearts content (as long as you turn if off when you're done).
If I were to host a bootcamp on starting a web app from scratch I'd do something like stand-up a T3 App https://github.com/t3-oss/create-t3-app on Vercel Hobby https://www.vercel.com . Not sure I'd even consider Heroku for teaching anymore.