I would totally welcome IRC back and USENET.

They're both still alive.

IRC: irc.libera.chat, irc.efnet.org, something rizon something; there's technically ircnet but don't bother

Usenet: eternal-september.org - you might find others after a while but there are no other major free text servers. If you pay another company for binary access (these are mostly used for piracy) you can also use it for text though.