Hundreds of small instances have disappeared in the last few months. If The Federation was still working I could scrape the current list of instances and identify ones that have appeared/disappeared since I last scraped it in July.
https://lemmings.world seems to be alive but doesn't fully load for me before the connection times out.
Here are a few down instances that I found manually:
I was going to mention geddit.social because that was my second instance (I had moved there from Lemmy.world in an effort to spread the load) until it went down with no info/reasoning.
Well, crap. I joined geddit.social after vlemmy admin disappeared with no notice. Fortunately, my primary account is lemm.ee and it has been solid. But it looks like I'll need to once again find another small back-up instance.