> Schemes like oauth2 might bring convenience and security in many cases, but will endanger net freedom overall.

Your statement makes it look like OAuth2 is inherently endangering net freedom.

This isn't true.

If OAuth2 was used ...

- for authentication (versus authorization) only AND

- AND by a select few providers (e.g. Google, Github, Facebook, Twitter) solely AND

- AND NO other privacy-protecting authentication methods (e.g. classic username-password credentials) are available

... THEN your statement has reasonable truth.