Admittedly independence day was a week ago so this is kind of late.
Most people in the left consider the US to be one of, if not the worst country in the (developed, unless you're a right wing strawman) world and, we have listed the bad things about the US many, many times, so I think a thread about the good things about the US would be neat.
The 3 main things I think are good are:
Honestly, I think party primaries where most people vote for president are good. While I do think they would be much more beneficial in a multiparty system as opposed to the US's 2 party system, I think it's better than having your presidential candidates be chosen by usually politicking with the party. I don't mean this to say the way party primaries are conducted in the US is the way because it isn't, but I think it's better than not having a primary.
I also think midterm elections are good, because it means that if people dislike the course of the current government, they can vote for that in a midterm. In the US, this means they only had 2 years of a Republican trifecta led by Trump as opposed to 4 like here in Brazil and I suspect a lot of other places. I don't mean this to say elections every 2 years is unequivocally good, and for such elections you would definitely need shorter primaries so elected politicians don't need to spend most of their time campaigning which I've heard is often what they do.
Lastly, I think the US is by far the country most concerned with things like electoral systems and methods, campaign finance, whether there should be an upper house or not (not that senate abolition is popular even among leftists, but it is much more popular than a place like, say, Brazil, where I live), and this is the third good thing about the US.
Of course, all of these originate from the worst parts of the US political system, but I think the fact that there's any public conscience of them existing is still a good thing.
One can argue the fact that the largest amount of influential companies being under US regulations means that if any positive changes to said regulation are implemented the entire world benefits (most obviously concerning the Internet), but the opposite is equally true and far more common.
There's also probably many good things about US culture, by virtue of that being true for most most cultures, but I don't know what US culture specifically is enough to list them.