I wonder how much they made from engineering practices such as https://github.com/actions/runner/issues/3792.

To spell it out: jobs can hang forever because of some ridiculously bad code on their end, they have a 6 hour cap, so that's 6 hours of billable $$$ per-instance of the bug (assuming it wasn't manually canceled). I know I've seen jobs hang forever regularly over the course of my years using GitHub for work.

Note: pretty sure this has been resolved.