This is something federation (e.g. Lemmy) solves, but it has its own signup fatigue that's higher than average. OpenID with arbitrary providers aimed to solve

This is something federation (e.g. Lemmy) solves, but it has its own signup fatigue that's higher than average. OpenID with arbitrary providers aimed to solve this, but never took off. I think I only used it with Stackoverflow. Instead, we got OAuth with Facebook and Google being the only widely-accepted providers. Layer a federated reputation system on top of OpenID and there could be a pretty robust anti-spam/asshole mechanism for independent forums and reduced signup fatigue.