the whole premise of OP is that this monitors people, and many organizations use TOTP, which one could also use without internet connections or phones AFAIK.
I’m in academia and I wish this is implemented more. Data breaches are getting quite common, and Github is so entwined in software engineering that it is critical to increase security measures.
I use gitlab ci mainly and dabble in github actions. Can you clarify how “Not even Github managed to pull that off”? IIRC, actions is quite featureful and it’s open-source, so I assume that can be run with self-hosted runners as well.