China became more liberal during the years after Mao, rapidly developing economically, transferring control away from the state in some areas and transitioning towards a market economy. Then there were the Tiananmen Square protests, the protests famously ending violently. In the years since those events, and maybe as a direct consequence, China has reversed some of the post-Mao freedoms, becoming more centralised and totalitarian once again. This is an example of the law of unintended consequences. The protestors did not want a more totalitarian and authoritative society; yet that was the result of their protests.
The participants in contemporary culture wars and climate emergency protests might benefit from looking at this and other historical events and thinking very carefully about their own actions – will their actions lead to the consequences they desire or will the law of unintended consequences once again lead to societal change in the opposite direction than they desire. The world can be complex and unpredictable.