TPM is a dedicated chip or firmware enabling hardware-level security, housing encryption keys, certificates, passwords, and sensitive data, “and shielding them from unauthorized access,” Microsoft senior product manager Steven Hosking wrote last month, declaring TPM 2.0 to be “a non-negotiable standard for the future of Windows.”
Gitlab is ok, and Codeberg is getting there.
I think the main thing that keeps me on GitHub is the network effect - all the other projects are there. They also have very generous (basically anti-competitive) free tiers.