Except that also for trusted publishing, they only allowed github in the beginning and eventually added a couple of other providers. But if you're not google or microsoft you won't be added.
These kinds of comments are borderline mendacious: you can observe, trivially, that 50% of the Trusted Publishers currently known to PyPI are neither Google nor Microsoft controlled[1].
If PyPI accepts two more likely ones, a full 2/3rds will unrelated to GitHub.
Once again: this is constrained by design. If you don’t want to use OpenID Connect, just create a token on PyPI and publish the normal way. You are not, and will never be, required to use this feature.