Capitalism is criticized a lot on here (especially by American users, it seems to me). Most of that seems well-founded, but I also have the feeling that most of these complaints are simply venting and not the first step to improvement.
So I would like to know what specific changes you (especially Americans) want to see from lawmakers.
Not an answer, but I do want to point out that your question may be missing a crucial point. Primarily: There are different types of capitalism. When people mock or complain about the current economy, you might hear about "late stage capitalism." That's because that's referring to the current type of capitalism that we're operating under. And Bernie Sanders believes in capitalism, too. But his belief is in a different type of capitalism.
This is all to say, when people complain, it may not even be that they want to replace capitalism, but even shifting to a more friendly type of capitalism would significantly remove a lot of strain from workers. I don't mean to imply that that's what the people you're referring to meant, but I think it is important to consider that criticism against capitalism does not necessarily mean a full shift away from capitalism
No, late stage capitalism isn't a kind of capitalism, it is the inevitable conclusion of capitalism.
Sanders is a liberal, liberals support capitalism.
Others are neoliberal, slightly more conservative "socially" (as if society can somehow be separate from economy), but still support capitalism.
And there are conservatives, who openly don't care about society (or anyone in it who isn't like them) and, you guessed it, they support capitalism.
They all serve the same system.
(edit to add: a system designed to never let anyone who openly opposes it get near a position of power)
Not being comfortable with this, or believing in the illusion of choice they give, and pretending like some capitalism is fine, is ridiculous.
Capitalism in its essence is about constant financial growth, which will always and forever be impossible in a finite universe. It might take longer to decay if you sprinkle some social policies and safety nets on to that, but at the end of the day it will always end in vast inequality, exploitation, and destruction of the environment.