Was there a bug or adjustment to artifact generation of some sort? I've had a few games recently off one of the nightly versions (not sure which) where there were no randarts to be found even til the 90s, and on inspection my artifact sets had tiny (single digit, mostly <4) generation chances for everything except for amulets, lights and rings whose only effect was 'not harmed by lightning'.
Edit: nvm, found discussion on github!
https://github.com/angband/angband/issues/4584