I lived in Beijing for 9 years and never thought "hey, my rent is too expensive!". I started paying 4000 RMB in 2007 and ended at 9,500 RMB in 2016 (on a slightly bigger place, in between I was at 6500-9000 on a much bigger place than what I ended at). Rental yields in Beijing are horrible (1-2%, the home I was paying 9000RMB a month on maybe would have gone for 7-8 million RMB at the time I was paying the rent), but most landlords didn't buy at current market prices.

the landlord would only increase if they know that the market can bear that price - aka, you cannot find an equivalent (or at least very similar) place for cheaper.