I don't think they're not just aware. But purely from scaling and distribution perspective it'd be wiser to start on cloud while you're still on the product-market fit phase. Also 'bare metal' requires more on the capex end and with how our corporate tax system is set it's just discouraging to go on this lane first and it'd be better off to spend on acquiring clients.
Also I'd guess a lot of technical founders are more familiar with cloud/server-side than with dealing or delegating sysadmin taks that might require adding members to the team.
I agree, the cloud definitely has a lot of use cases and when you are building more complicated systems it makes sense to just have to do a few clicks to get a new stack setup vs. having someone evaluate solutions and getting familiar with operating them on a deep level (backups etc.).
Also I'd guess a lot of technical founders are more familiar with cloud/server-side than with dealing or delegating sysadmin taks that might require adding members to the team.