People who become politically active in China end up disappearing regardless of party membership. I mean, you realise the "party" in a communist state is nothing like a political party in democracies? The word used is the same but their mechanics are totally different.
We had a one-party system in Yugoslavia. Today we have one ruling party which almost always wins the election and being a member will give you perks and advantages. Small parties are there mostly for the decor and coalitions. Sometimes the opposition will win at the city level, and then the county and state ruled by the party in power will do everything to undermine any disruptive actions, prevent advancements and things just stay blocked until that party wins the local election and unblocks the changes to attribute it to themselves. Also, significant infrastructure work often awaits for just before the next election, for better optics, or the government will choose where to invest public funds based on publicity and not the actual needs of the people, everything to secure the next election.
Theoretically at least you could join the party and become politically active in your local branch, no?