I've been using self-signed certs on my websites for 20 years. Part of the problem is that the HTTP/3 implementations do not allow the use of self signed certs. CA based only.
For the last decade or so I've gotten about 1k hits per day on my self-signed HTTP+HTTPS site. Random people will click past the scare tactics of modern browsers re: self signed if the topic is already technical and the demographic understands browsers are stupid. But all these people would be unable to visit under HTTP/2 or HTTP/3 only.