Folks regularly show up in HN comments during these discussions stating the opposite—that it's categorically better for all sites/projects, now matter how inconsequential, to stay online. It's weird.
This includes some of the TPTB, too. Occasionally, though, someone'll say the quiet part out loud. E.g. re fly.io:
> putting work into features specifically to minimize how much people spend seems like a good way to fail a company
I think being offline is a lesser headache than a large bill, especially for those who are inclined to a free tier to begin with.