Maybe Usenet can have a comeback.
It sorta has been since a few years now. However, moderated groups will always face the spam problem. Spammers only forgot about it for some years because ISP's rarely include access these days (and text groups had been fairly dead by that time).
One difficulty these days is that I am unsure how to suggest to add new newsgroups, and it seems also some other people are unsure too. (I think someone wanted to add a newsgroup for the COVID-19 pandemic, but seemed to be unsure how (I think they wanted to add it to the alt.* hierarchy); I checked just now and the Usenet provider I use does not seem to have such a newsgroup at this time. I would think that you would need to contact the hierarchy administrators, probably. Unfortunately, I do not know how.) Of course, this is not a problem with existing newsgroups.
In the case of spam, there still is some, but it seems these days the spam on Usenet are all from Google Groups. (There are legitimate messages from Google Groups too, although many of the legitimate messages come from other providers.)
NNTP does have many advantages. It is better in many ways than web interfaces are, and I think also better than mailing lists are too, although you can have all three if wanted. I know I am not the only one who wants this, to have NNTP for these things (I have seen others both on HN and elsewhere; even on Usenet they suggested even isolated forums should have a NNTP backend, and I agree).