A lot of people don’t know, I certainly didn’t for a while. There’s monetary incentives to having public team projects in Azure DevOps. A public team project is meant to support open-source projects. It’s clear Microsoft is heavily invested in open source.
Public team projects can also be a great way to house prototype/demo projects. I use them all the time. Of course, I keep out proprietary information. Why? Because there’s a nice incentive.
Free and unlimited build minutes. (Usually you get 1800/month for free)
Up to 10 parallel jobs. (Usually you get one job at a time on hosted agents for free)
At the time of writing this, it’s roughly $40 a month to add additional parallel jobs using Azure DevOps’ hosted agents. Ten parallel jobs is a _lot_ more.
If you’re worried about polluting your Azure DevOps organization, you could also create a separate Azure DevOps organization to house your playground projects. It would certainly inherently simplify the segregation of prototypes and production-ready apps.