The problem is sizing and consistency. When you're small, it's not cost effective to overprovision 2-3 big servers (for HA).
And when you need to move fast (or things break), you can't wait a day for a dedicated server to come up, or worse, have your provider run out of capacity (or have to pick a different specced server)
IME, having to go multi cloud/provider is a way worse problem to have.
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