Sometimes I have hobby projects that need more than the free tier of Heroku. I get a lot more bang for buck somewhere like Vultr or Digital Ocean compared to Heroku.
The standard tier at Heroku is 512MB RAM for $25. Over at Vultr, I can get 2GB RAM for $20. I also get 45GB of SSD, so I don't have to pay for something like Amazon S3 to store uploaded files.
If you're building an actual product, I agree with you, pay Heroku and focus on building your product. However, there's a lot of people looking to host smaller projects that wouldn't break even financially if they used Heroku.
If Heroku works for you, that's fine, but for lots of people it doesn't. For example, Heroku only supports HTTP, not TCP. There are a number of technical limitations Heroku places on apps that other platforms like Flynn don't.
There are lots of reasons why users need a different, or especially an open source, PaaS.
Some users run into scaling problems when their products grow beyond a certain point. Others want to have more control over their infrastructure for compliance, governance, or other administrative reasons. Others have huge deployments and want to save money by using their own cloud accounts.
It varies from customer to customer, but for many Heroku isn't an option or isn't the best option.
Totally with you on this - all pretty valid points; but, I'd say Heroku does still work for a lot of people, especially if they can get past the cost (which, imho is worth it from a focus and time point of view).
I used Heroku to get my project off the ground, but costs are adding up now. What holds me back from migrating off Heroku is I don't have time to learn devops properly, kubernetes, maintain servers etc.
This looks like a nice middle ground for me. I should be able to migrate to flynn on Digital Ocean pretty easily (easy deployment of flynn infrastructure, same buildpack system). I'm sure there'll be regular maintenance involved, but it looks like nowhere near as much as a roll your own kubernetes cluster.
