Replying to @ricci@discuss.systems
@ricci So, my crawler has been running for 5 years, and it also pulls data from other sources like the-federation.info, fediverse.observer, fedidb.com etc. Its database has 44142 alive nodes and 777384 dead ones, so the answer is 5.4%. If .gab.best and .cheeseland.xyz are excluded, then only 98621 nodes are dead and the answer is 30.9%.
Someone in the thread suggested that nodes might be pruning their peers lists from dead nodes. Judging by the negligible difference between Evan's number and my number, no pruning is done.
BTW, my crawler currently tracks 22 newly discovered nodes, i.e. ones that were seen in someone's peers list but whose NodeInfo hasn't been checked yet. I'm happy the Fediverse keeps growing _^