The matter expert of AWS will click a few vms and a managed database in a few minutes enabled snapshots and is done (and not really an expert)
The matter experts in a self hosting company will setup something. They might know how to do it right but probably not.
And just because I can do it myself very good, a lot of people can't.
The DB experts in my experience were to 80% people barely even getting databases right and the last 20% were the real experts keeping the shit running
And even in big companies I have seen shitty infra teams. Old software versions of the management tool, missing features, exorbitant cross charging, not enough hardware etc.
Is self hosting cheaper? Yes.
Should you do it?
Yes if you can afford good people and take it serious.
Don't blame cloud. You are not on cloud if you would be smart enough and capable enough of doing so anyway.