That's not "broken". Docker Inc. is just rate-limiting access to their service. A service which, for what it's worth, has been used to bootstrap the technology required to sustain a pile of money for a lot of people.

There are other container repositories, and as you said, you can build your own containers and run those.

It's a dependency bottleneck that requires a pretty hefty amount of money ($9/mo) to get around

You can just host your own registry, or use a managed one like AWS ECR (which has a pretty good free tier).