Picking an arbitrary price point of $200/mo, you can get 4(!) vCPUs and 16GB of RAM at AWS. Architectures are different etc., but this is roughly a mid-spec dev laptop of 5 or so years ago.
At Hetzner, you can rent a machine with 48 cores and 128GB of RAM for the same money. It's hard to overstate how far apart these machines are in raw computational capacity.
There are approaches to problems that make sense with 10x the capacity that don't make sense on the much smaller node. Critically, those approaches can sometimes save engineering time that would otherwise go into building a more complex system to manage around artificial constraints.
Yes, there are other factors like durability etc. that need to be designed for. But going the other way, dedicated boxes can deliver more consistent performance without worries of noisy neighbors.