exactly, even for just occasional dropping-in on an ng, 4 to 5 weeks
should be adequate and I can't see many ISPs failing to deliver at
least that - after all, text-only is miserably small beer, the entire
global output would probably fit on a 10Gb hard-drive.  Beyond that
and for archiving nothing will compete with google since they claim to
go back to year zero (does anyone remember compuserve? - I had my
first account with them.  It was dire!)

A good usenet client is far easier than google groups and it's more or
less immediate. You post, it's there within seconds to re-read.  If
your ISP doesn't offer it, kh, then vote with your feet.

Passé? Maybe. Web forums (fora?, I've never been sure) could gradually
leave usenet with something below critical mass for survival.  I dip
in here and there myself with special-interest enquiries and there are
plenty of groups out there seeing no more than 2 posts per week.  But
read-only seems a bit mean.  Only marginally more useful than
write-only?