The thing is that most baremetal hosts are exactly as the parent described - annoyingly slow, manual, etc.
Hetzner is a little gem here, where they have a large selection of pre-specced machines that are ready for automated deployment, and they also show you a pool of cheaper machines that were returned by other customers/terminated/cancelled and automatically wiped with varying specs that you can also automatically pick out via API (this includes random upgrades that the ex-customers added).
If you manage to fit in the square hole that their automation occupies, it's a great fit.
EDIT: oh and also server buying/renting/installing is probably the smallest problem when running your own metal/colo or renting servers. a big use case for clouds is, data sharing between hosts via object storage/moveable disks, etc. which is non trivial on "bare metal/colo/renting" and that is just one use case.
But sometimes, you just need a ton of bandwidth, compute, RAM, etc. and don't care about managed services.. I don't think there's a single major cloud provider that will give me a 2TB Intel DC SSD to use 100% of r/w for $20/m. And not being billed per-GB bandwidth is a massive relief for certain use cases.
