In my country, Italy, all online public services already must accept government-issued digital IDs only, by law.
They come in two forms: SPID (which is just username and password + TOTP, issued by private companies on behalf of the State, but allowing you to change your provider without becoming "a completely different person" [1]), and CIE (which is the new national ID card, and can be used as an electronic ID using any NFC reader).
Additionally, some services allow to log in using equivalent eIDs from other EU countries [2].
They come in two forms: SPID (which is just username and password + TOTP, issued by private companies on behalf of the State, but allowing you to change your provider without becoming "a completely different person" [1]), and CIE (which is the new national ID card, and can be used as an electronic ID using any NFC reader). Additionally, some services allow to log in using equivalent eIDs from other EU countries [2].
[1] https://www.spid.gov.it/en/frequently-asked-questions/
[2] https://eid.gov.it/?lang=en-001