Subways are for locals. The foreigners will opt for taxi's 95% of the time. Only a few brave tourists will do the subway. I may be wrong, but even I steer away from the subways. Don't know routes and am afraid of getting lost. I did download the subway map in English for Shanghai. I did take the subway, but was worried the entire time.
Buying tickets for the subway is difficult if you don't speak Chinese or don't have a map to point to a stop so they know what to sell you. I am not new to China, and I still prefer taxi's. The cost is worse but ...
I took the subway in Montreal and almost missed my stop because people wouldn't move to let me get to the door. That was 16 years ago and I still remember!!! I was living in Montreal but didn't speak the language there either.