To expand on this a bit: impeachment in a liberal democracy isn't meant as a tool for the people to remove a president that doesn't serve their interests. It is meant as a tool for the wealthy and powerful (the venn diagram there is almost a circle) to remove a president that doesn't serve their interests. Look at who's paying the congresspeople and their parties. Their donors, for all intents and purposes, get to decide whether to impeach. (those same donors also control the vast majority of the media, so they can shape public opinion/manufacture consent too).

So far the wealthy have no reason to dislike Trump, so he'll stay in power for a while. If that changes (due to dementia or otherwise) he might get impeached. I think the most likely way for that to happen is if his dumb ass crashes the real sector again in a way that hurts the rich, a-la 2020. It sadly comes down to a game of chance here: his austerity measures and trying to "save a buck" on vital government functions make a disaster more likely, but not guaranteed.

It's the same in South Korea: the only reason the president was removed is because his erratic actions while trying to cling to power hurt the interests of the wealthy directly. The people had very little to do with it; it could have very easily gone very different, if the military (which was present at the time of the protests) got slightly different orders, or the congress people got slightly different whispers in their ears.