That's a weak argument. If the institutions can collapse because a few powerful people can work against it, then the institution has already failed in the first place.
Trump and the general rise of Populism is not the cause of the fall of Western democracies, it is a consequence.
You don't seem to grasp that the answer isn't "oh well, Western democracies were just going to fail I guess"
The answer to what?
The answer to institutional collapse, the topic of the post to which I replied.
You're going to have to show your work on that one. Western democracies are suffering not because they are failing, but because they have been chipped away at for decades by fanatical right wing billionaires intent on eliminating taxes and securing their place in a perpetual oligarchy.