Why can't people just tell Trump that they've done these things, and then just have like a shadow government that actually works. Why are people actually taking orders from this psychopath?

He's actually starting to threaten World War 3 again, and quite a lot of Americans seem to be going "oh well obviously I don't agree with it but what can we do". Nothing, that's what you do, you simply do not do what he tells you to do. Ignore him.