I'd say that running infrastructure in the cloud still requires the same deep understanding of what's going on under the hood as running your on-prem infra. A lot of annoying things are taken out: some stuff patches automatically, some other things have an easier updating procedure (and obviously the "physical" aspect is taken care of).. but you still only get the basic elements for a proper infrastructure. Your servers need an environment set up, you need to build a network, add load balancing and replication, monitoring etc. etc..
You can provision some of these things from cloud providers, but your infra is going to go to shit unless you actually understand what they're really providing you and how to use it. If the only thing you can do is upload a docker image to a cloud provider and click the "create server" button, then that's not really infra work at all. It's like Wix for sysadmins.
