I don't like Trump either. Nearly all of your complaints about his character are true.
Nevertheless, as we arrive at what seems likely to be the end of his presidency, it's worth noting what our reaction to him reveals about our collective values and character--or lack thereof. Many libertarians, genuine conservatives, and leftists are convinced he is the worst president of our lifetime.
He is certainly the worst person to be president in a long time. But is he the worst president?
I worry here that people are so irked by his style--by his bombastic promises, but his higher-than-normal propensity to bullshit, by his lack of grace, by his inability to feign empathy the way normal politicians do when they seek the power they crave, by his apparent comfort with authoritarianism (which seems to come from thinking he should run a country like he runs his family businesses)--that they spend little time look at the substance of what he's done.
So, a good starting exercise in evaluating his presidency would be to ask yourself what you would think of him if he didn't have Twitter and never gave any public interviews. Imagine that instead you simply had to evaluate him on the basis of the policies he enacted or blocked. Imagine you had never heard him speak or read his tweets.
On that basis, even though he did bad things, he is not in any clear way the worst president of our lifetime. Bush II pushed through the Patriot Act and started the disastrous, failed wars in Iraq and Afghanistan. (Iraq is still rated as an authoritarian country in the Democracy Index.) Though Clinton was probably a better president, he oversaw the 1994 crime bill that is to a significant extent responsible for the problem of mass incarceration. Reagan's ramping up of the war on drugs has been a humanitarian disaster, which is also responsible for serious increases in crime and led to a militarized police that in turn is causing the Black Lives Protests today. Trump mismanaged COVID-19, but realistically, how much better could he have done? It's not as though we'd have only 20,000 deaths had Clinton II been president. He was slightly more cruel to illegal immigrants than Obama and previous presidents were, but the media made a bigger deal of it because they hate him. (Keep in mind I favor completely open borders and believe illegal immigrants may kill border patrol agents to escape capture. I am not excusing him.) He did massively run up the national debt, which seems to go along with his normal business practices. The shutdowns did massively screw over the American poor (especially minorities), but most of you seem to think the shutdowns didn't go far enough, and you sincerely tell yourself that had you been in charge, you would have redistributed enough income to the poor to fix that problem.
No, that's not a full accounting of Trump or the others. But he didn't start WW3. He didn't turn the US into a fascist country. He didn't produce the horrors many of you predicted he would--and, indeed, you never believed he would. (You were just grandstanding, because hating on Trump helps prove you are a loyal member of our political tribe. I get it. I do it too. Fuck the Yankees!) But in terms of the substantial laws and policies passed, Trump has to be better than Bush II, at least.
"Sure, Trump didn't start a horrible humanitarian disaster of a war, but he tweets mean things!"
However, this brings us to the question which forms the title of this post. Trump's crude style--his nastiness and utter lack of statemanship--has clearly helped delegitimize the US, the US government, and the presidency. Foreigners' approval ratings of the US declined and stayed down. European leaders say that they can no longer count on the US. Internal divisions and polarization grew stronger within the US. (That said, to some degree, this might not be Trump's fault--it might be that we're overreacting and acting like hooligan assholes. Trump derangement syndrome is a real cognitive failing on our part.)
Still, insofar as his rhetoric and style destabilizes American democracy or the world order, and insofar as it does so as a rational reaction to him rather than as a result of Trump derangement syndrome, then at some point, perhaps style becomes substance. In the abstract, we might say that even if President A passes better laws than President B, if A causes the country to collapse into civil war and B does not, then B is better than A. So, we understand that style can at some point become substantive.
Are we at that point? How would we know? Given how the exaggerated emotion displays, fatalistic but false predictions, your masturbatory desire to call everything racist, and overall irrationality most of you have exhibited over the past four years, why think you're in any position to judge?
Again--and I shouldn't have to say this--I think Trump is terrible and unfit to lead.