That's just the point. Selfhosted runners were the alternative. The only alternative for "runners" is Github-hosted, 200%-markup runners.

Now the only alternative is to move builds, CI, etc. off of GitHub's platform entirely, and maybe your source control as well. In other words, a big pain. Github seems to have entered peak encrapification: the point where they openly acknowledge rent-seeking as their product approach, fully deprecating "building the best, most reliable, trustworthy product." Now it's just "Pay us high margins because the effort to migrate off is big and will take too long to break even."

Basically the modern day Heroku business model.