Meltdown strikes back: the L1 terminal fault vulnerability

You can run AWS instances on separate hardware, or even dedicated hardware. It just costs more. (And some fancy AWS functions aren't available at the higher levels of separation, though I'm not sure on specifics.)

At this stage I think it'd be remarkable if IT in general goes back to in-house hosting from the cloud providers. Renting compute just makes IT management so ridiculously easier. Particularly when you get into Terraform etc, where you can literally program what infrastructure you have. I haven't been in a machine room for over five years now, and have no plans to go back.