Yep copying will sure bring the cost down. I guess back engineering costs are cheaper. But regardless of just copies, Shimano components are cheaper otherwise no one would buy them. If your only earning 5000 yuan a month you don't want to blow too much money.
So i guess the fear is things will break quickly, swing arm etc. from one of the vids the welding looked a bit sloppy, but is that more aesthetic? Would be good to hear from someone who has bought one