The problem is...
...cost. The cloud cost so much more than on site unless you're a small business then it might be worth it. But you still need to factor in the cost of the engineer/s to support it. Problem is, directors don't see this and just are under the delusion that full cloud is cheaper.
Sometimes I long for the 90s and 00s to be back, I'm starting to fear I'll be out of a job I enjoy soon.
Mark Russinovich who I really like as a developer said it sadly, and made me slightly go off him. Because he's at the top of his game and moving on as the tech is, some of us aren't as bright as him so struggle. But in an interview he said something along the lines of "A lot of engineers don't want to move to the cloud because they know it will put them out of a job. But they have to deal with it". I couldn't watch the rest of the interview after that. Easy to say when you're as bright as a button.