and I know they're already beholden to domain registrars but that's not really a good argument against adding an additional, arguably unnecessary cost to someone who just wants to run a hobby website.
You are not required to have a domain to have a website; just using an IP address works fine too, and - more importantly - unlike what would happen if the proposal to ban plaintext goes through, browsers don't give big scary warnings if you use an IP instead.
We had an internal dev' server. We generated a certificate for the IP address using our internal CA. We installed the internal CA on client machines+inside Firefox, Chrome and IE worked perfectly, Firefox bounced the IP address "domain" certificate even though it was valid by all metrics we could measure. It just claimed that the IP address of the host and the certificate's CN weren't matching even though they were. We tried it as the alternative name also, no dice.
We finally had to assign the machine an internal domain name using our DNS servers and redirect from the IP address just to fix Firefox's HTTPS issues with IP addresses. It is damn stupid and no other browser acts this way.
You are not required to have a domain to have a website; just using an IP address works fine too, and - more importantly - unlike what would happen if the proposal to ban plaintext goes through, browsers don't give big scary warnings if you use an IP instead.