I’ve been following the development of the drivers license sharing system from Apple where different fields can be selected; are there any implementations of PKI based identification systems where multiple certificates can be generated and revoked when compromised?

I’ve often thought that replacing the US social security number with a more robust root key makes for a fun thought experiment. Hard to imagine how such a system could securely serve so many people but passports with embedded chips seem to be doing okay.

Not in the US. Several EU countries have PKI systems integrated with identity documents that let the requester to ask for age (for example) and then only age is supplied. But their PKI systems are for the whole ID document.

As for the passport, the key/PIN you need to authenticate to the chip are printed on the page with the photo. Otherwise "hackers" can only determine nationality of passport. The standard is ICAO 9303.

https://www.icao.int/publications/doc-series/doc-9303

SSN was never intended for identification. My original card, issued in the 1970s was clearly marked "not for identification". In the original numbering system, the first 3 digits identified the office/area where the card/number was issued and the next 2 digits identified the filing cabinet. 700s were set aside for railroad workers (until 1963) because the legislators did not want railroad workers to be included in social security.

https://secure.ssa.gov/poms.nsf/lnx/0110225045