Protest can lead to change in America, but before it does the American intelligence system starts visiting and assassinating people. This is well documented.
The US government is a collection of a few, not that many, disparate power bases that nonetheless have extreme similarities. Which is why, for example, COINTELPRO was a bipartisan effort.
The Chinese government is absolutely susceptible to radical change because of organized protest. Not peaceful, because violence would get involved, but the disintegration can be put into gear as a result of peaceful protest. I don't see why this is absurd, it happened to the USSR that had a political system that is identical to China.
And yes, the Chinese tyranny is honest, they tell you upfront that they will suppress protest as long as it threatens a few key points, and they generally stick to it.
The American local and federal governments have never done radical reforms without violence or the threat of violence. I don't see prohibition as a radical reform, and neither is the relatively inconsequent expansions of minority rights except for the 60s and 70s, which definitely involved the threat of violence.
I'm not claiming that no change can be done from popular will - neither in the US nor in China, though more can be done in the US. I'm claiming that radical change that threaten the shared interests of the power base will, in both cases, be opposed by lethal force. And they will.
And no, this isn't limited to single protestors. The US National Guard has opened fire and bombed whole crowds in the beginning of the 20th century when organized labour was a threat, and figureheads of protests were and almost definitely still are subjected to intense surveillance and often threats or even actual violence - it's absolutely not a single protestor that is effected, it's everyone in the US.
But yes, if you state the assertions without the necessary nuance they sound absurd. This is a discussion that requires a lot of nuance and it would be nice if we could steelman each other.