Most tech companies (especially startups) don't.
So KYC as a service is certainly a thing, and I know of two: Tracesmart & Onfido.
I haven't used PostID yet but with WebID you basically have a Skype video call where you show them your ID.
[1]: https://www.webid-solutions.de/en/ [2]: https://www.deutschepost.de/de/p/postid.html
The best was when they asked me which model of car I had owned... and listed two cars that I had owned... I could only select one.
These records can be flat out wrong too. The DMV associates a car with my address that I don't own, for example. I think this happened because the owner never changed their address with the DMV. Or someone could have just fat fingered something which gets populated to other databases with data sharing.
It's harder online when you don't have the same ability to interact face to face.