Going to take off the objective hat and talk as a liberal. The answer I give to this is for the US, the President is both the head of state and the head of government. As is clear from recent articles about Trump's manner in the white house, his team is very much making many of the small policy decisions while Trump gets to strut out as the figurehead.
So yes, Trump stepping down wouldn't mean much difference when it comes to his role as a head of government since his team seems to be handling that, but the head of state is still a very important role. Don't forget, he said,
"I just start kissing them. It's like a magnet. Just kiss. I don't even wait. And when you're a star they let you do it. You can do anything ... Grab them by the pussy. You can do anything[,]"
essentially describing sexual assault, emphasized by me. Not to mention his poor demeanor, his lack of likeability, his unpopularity, the fact he was a reality-TV star. Having such an individual represent the nation is an embarrassment and does not inspire confidence in the nation nor does it abroad. Understand, no international body would respect Trump if he weren't the President. He does not prop us up as a country, he receives respect because we prop him up, and even then, he still depreciates his image by trying to project and strengthen his fragile pride and by involving himself in frivolous engagements on Twitter.
So yes, having a different head of state would be beneficial for us, at least in our view. It would not make much of a difference in terms of actual policy, but it would give us with a better representative, which isn't a difficult bar to exceed.
EDIT: I almost forgot, despite the politics of it, I do personally feel that a conflict of interest as a President is detrimental to the role as the head of government. We have already seen for example his orders on DAPL, which he still owns some shares of, a direct conflict of interest. And worse, of course, there are his foreign investments, which is worse from a national security standpoint. Sorry, but a head of government should represent us, not their own personal financial interests. You don't even need all my feeling about Trump as a figurehead, although that is important, but his conflicts of interests are a significant issue with him as an elected official.