Probably because you're in a union in a capitalist society. Unions are lacking when missing a leftist ideology. Unions are a hold over for the working class and should be used as a stepping stone in society until an economy of worker co-ops are created.
That's because it's being applied to Western standards. China spends a crazy amount of money on social welfare and government assistance. Minimum wage is around or less than 2000 Yuan a month around the country, yes. But, that's completely ignoring currency exchange rates and cost of living.
Cost of living in Shanghai and Beijing are around 4,500 Yuan. Which means a couple or two roommates can live on minimum wage in the biggest cities. Compare that to minimum wage and cost of living in New York City or LA which is $1,280 a month, costing $4,300 and 1,342 a month, costing $5,576 respectively.
Tldr: how much money you make is only relevant when compared to your cost of living. It's not hard to live in China on $300 a month.
That's solidarity right there