99% of the people who participated in the 1989 anti-corruptipn protests are fine. They went after the figureheads who tried to skew the protests into being pro-democracy (coincidentally, most of these people ended up in the US and were offered asylum). Casualties primarily occurred in standoffs surrounding the square - police were strung up, molotovs were thrown, windows were smashed, national guard opened fire, and the (rather inadequately trained) riot police got handed equipment and told to deal with it.

It was widely seen at the time that Deng Xiaoping's policies for economic liberalization were harming the average person by allowing some regions and some people to get rich before others. What that meant in practice was that local government officials would grift the crap out of things... So the protests happened, Deng Xiaoping was forced to step down, and the pace of economic liberalization was slowed. The point of the movement was not for change of government or democratization - that skew happened incredibly late in the process, but most notably the protests did lead to substantiative change in China's government, policy direction, and led to the most senior officials stepping down.

The protests... Worked. Just like the white paper protests worked in ending COVID-19 restrictions. Just like hundreds of protests every year help bring attention to local government officials' corruption. The protests led to substantiative change in policy, had repercussions on the relevant government officials, and, fundamentally, did exactly what a protest is designed to do.