> I am very confused by the movement towards using the cloud for everything, because I work at all sorts of scales, and can't find a cloud host who works well for any of my use-cases

Just a couple off the top of my head:

1 - Incredibly large infrequently run / ad-hoc workloads

2 - Companies with such a horrendous internal work environment that they can't retain decent technical talent, where managed services can substitute to some degree.