I am a grumpy grey beard no doubt but I still maintain: most websites do not need more than a single server -- certainly not more than a single database server. And, for most, a few hundred dollar dedidcated server is aplenty. Apply YAGNI until blue in the face.
I run a Dokku instance on a Hetzner server and it's been fantastic, I host 10-20 of my projects with thousands of daily users there without it even breaking a sweat. My only regret is that I should have used a single database instead of one DB per project, but I was lazy.
True, most websites do not have this problem, because most websites do not drive revenue like that. There are plenty of use cases where you need five nines, but only within limited not-24/7 time windows.