You’re missing a few salient points.

1. Geography. I hear this from Europeans all the time, usually in discussions of why don’t Americans travel more and visit other cultures. They just don’t seem to get the practicalities of geography until it’s pointed out to them. Our nation is 2680 miles across and 1582 miles tall. That’s a lot of area. Not including Hawaii or Alaska or any of the protectorates. It’s just not feasibly practical for most people to go camp out at DC until he resigns. It’s not like the citizens of Marseilles storming off to Paris, or folks from Birmingham laying seige to London. So let’s not pretend like it is. 2k+ miles for the most populous state (California) to go to Washington. So it’s more like an eastern European making a quick little trip to Japan. Few people do that easily without months of planning either. And certainly not for an indefinite stay.
2. Our political system does not really recognize “no confidence” like other governments. In fairness, this is the first time it’s ever been a real problem. In other words, even if half of America went to Washington per your suggestion, it would not lead to his resignation because the only “no confidence” the public has is to not re-elect or to impeach. He’s already been impeached. (See point 4). He can resign, it’s true. Nixon did. But there’s no other precedent nor a means of forcing the issue, like a public referendum. Which brings me to,
3. Does anyone actually believe he gives a rat’s ass about the American people enough to do something that does not benefit him? For someone so eager to point out the flaws of America with such glee, you’re not really paying attention, dude.
4. As I said, he’s already been impeached. This should have fixed things, however, it did not. Why? Because Trump isn’t the problem, he’s the big showy head bloviating over emerald green flames. The problem is beyond him. It’s the guy*(s) behind the curtain. The impeachment trial should have made that plain for anyone who didn’t already have a basic handle on things. Which brings me to,
5. Your entire premise depends on the notion that Americans want to stay as we are. I find myself wondering if that’s true. You criticize us for destroying democracy across the globe and there’s truth in that, but it’s an unbalanced criticism. We are not ignorant or uncaring on the whole. A third of the country wants and supports a theocracy, no matter the cost. I don’t think they grasp the cost but I may be wrong. A third of the country wants us to embrace Constitutional ethos in fact and daily life as well as in speech. We want America to be America, you know? A third of the country is caught in a tug of war between two opposites who increasingly cannot live together anymore. That’s not on Trump. He’s just having fun and enriching himself at our expense like any other narcissistic sociopathic frenemy. Our problem is as much more our neighbor as it is who sits in the Oval Office or in Congress. How would a Presidential or Congressional resignations help that? And when it’s split like it is, who’s to resign?

I don’t know what’s going to happen, no one does. It feels like the run up to the civil war in many respects. But secession can’t happen like it did then, since the divide is also very much between city dwellers (Democrats) and rural residents (Republicans). How would we split?

I don’t think he’s going to be President again, even if he gets elected. I actually would be shocked if his re-election did not lead to massive riots (assuming we’re not having food riots and housing riots before then) across the country aimed at anything Federal. I’m thinking the Republican party has pretty much destroyed itself for their folly. I’m thinking that this can’t last and we’ll either make it through intact or we won’t. But I’m thinking at least a third of us will never accept an authoritarian government. In such a case, democracy will live, it just won’t be as the United States of America.

This has been brewing for a very long time. Since Reagan fell into bed with Evangelicals. This was why the founders wanted to keep religion out of politics. It just doesn’t go well.