I used to think like this. However, I realized Executive Orders have a lot of affect.
So do articles of impeachment.
My point isn't that Donald Trump could be a low-quality President, but that the promoted level of doom and gloom and disaster is greatly overstated and fails to consider the balance of powers among the branches of government at a minimum and further fails to consider other potential problems associated with policy implementation.
Trump may throw a tantrum wanting some policy or other, but that doesn't make it so on the spot. There's a whole apparatus of bureaucracy that has to implement it, and truly loony ideas won't get implemented or at least not before they can be challenged in court.
I think the "disaster" argument also fails to consider Trump as even rational at all, as if he were really an irrational and unstable person. I also don't buy that, either. He may have a big mouth, but you don't get to where he is in life right now (fabulously wealthy, still in control of his company, and on the Republican ticket for President) if you are actually incapable of making rational decisions. Nor does it consider the persuasive ability of career people -- diplomats, advisers, military people, etc, who would counsel him against truly dangerous actions.
None of this is meant to advocate for him -- he's obviously a boorish loudmouth, but the notion that he can single-handedly "destroy America" is a bill of goods promoted by his opponents as a scare tactic because positive selling of Hillary is so difficult given her lack of likability and dissembling on so many issued.