Replying to @patterfloof@meow.social
An annecdote about this:
A week ago, my personal site went down for the first time in over two years.
My hosting provider Vultr restarted all their VPSs due to a Linux vulnerability, and I forgot to enable my systemd daemon to restart on boot.
I was camping without cell service at the time, so the site was down for a full day and a half, say 36 hours.
Some back of the envelope math puts that at ~99.8% uptime over the life of the website.