Free private repos on github is relatively new, only introduced after a rise in popularity of gitlab (which has free private repos).

Seems like github is too popular for itself.

I know you said "relatively", but it's been seven and a half years: https://github.blog/changelog/2019-01-08-pricing-changes/

…and encountering the same issues most likely.

Fair, but the point is GitHub’s model is:

Free Users use GitHub => when a company needs source control => all their coders use GitHub => company buys expensive enterprise contract.

If there’s less of an advantage to using free GitHub then that funnel works less effectively.