maybe, but tangled knots actually federate. you could contribute to repos on knot.ghostty.org and knot.tangled.org with the same account. no other platform permits one identity across instances.
I think the key point is that it's one atproto login/did to many forges 1:N in tangled.org's "knots" network without the reliance on a single host provider/instance like GitHub/GitLab/whatever as a single point of failure.