"Why don't Americans protest more" is a funny question because Americans have nothing and no one to rally around, no coherent ideology beyond a vague sense of patriotic duty, a lot of them are ignorant by design, many more are exhausted by design, protesters are universally portrayed as violent terrorists, they get no political support or protection (unless they're Nazis) and they get brutalized by cops with military gear whenever they do show up in numbers, no matter how peaceful.
The US is a country that looked at the Civil Rights Movement and the Vietnam War protests and decided it was never going to allow that again, even if it has to kill and jail everyone involved.
Meanwhile, heavily armed white supremacists can march down Main Street all day long, masks on and everything, and receive full police escorts, protection, and support.
They can occupy state capitols and the police response is a yawn and "LOL, I hope they fuck somebody up."
The January 6 attack on the US Capitol was known about by federal law enforcement well in advance and there was zero preparation for it, leaving a handful of capitol police and Secret Service to defend Congress.
So you have to understand, you can protest all day long as long as you're harmless, i.e., you don't threaten the white supremacist power structure and its money. Hell, if you're a fascist, you almost have permission to do political violence in this country.
So when people ask me what it would take to get an effective mass movement in the streets, they don't understand how beat down the left, young, and marginalized people are in this country and how severe the reprisals would be.
The US is a bit like a hybrid regime where the "regime" are white wealthy elites regardless of party affiliation. There are elections, etc. but power, protest, and violence flow in one direction only.
If you don't want to get shot, you make yourself seem as harmless and apolitical as possible, at which point you're obviously ineffectual at creating change, which is entirely by design.
And if you don't, you get demonized by the entire system.
The problem, like all hybrid regimes, is the inflexibility of the system promotes widespread disillusionment, anger, and frustration and if the lid ever does blow off -- who fucking knows?
I don't know where that tipping point is in the US. Nobody does. And nobody knows what would happen afterwards. But a lot of people are afraid of it.
You're more likely to see the fascists doing pogroms and death squads in the street first anyway.
Some college students doing peaceful sit-ins at their local universities shouldn't get much attention, but because they were protesting Israel's genocide in Gaza, which has bipartisan support, they got the riot cops called on them and the Democratic president referred to them as antisemitic terrorists.