A long time ago there was this “web of trust”, I don’t think it exists anymore. Was one of the big CA and you could get different certificates through some form of vouching, I think it even went as far as meeting people to show your ID and then they sign you or something. As it was run by a big CA, not really distributed but IIRC they kept their involvement minimal. It’s been a long time but if you’re curious maybe look into that