Comment by actionfromafar a day ago
There are or were two kinds of people using self-signed certificates. The vast majority used to be "I don't know how or can't afford to get a certificate chain cert."
Now, with letsencrypt, what's left of the "can't afford group" is "I can't be arsed to update my config yet".
It’s not. There’s LetsEncrypt, ZeroSSL, BuyPass, SSL.com, and Google Trust Services[0]. The ACME protocol is standardized and you can point your client at any of these at any time, and other providers can begin providing certificates at any time. Some tooling[1] even uses other providers by default.
[0] https://acmeclients.com/certificate-authorities/ [1] https://github.com/acmesh-official/acme.sh/wiki/Change-defau...
Just because many people using self-signed certs are at the "don't know" stage isn't a reason to invalidate them.