I think everything becomes slightly easier to decipher if you put yourself in their shoes.
what is the ultimate goal for Trump? guy is a self made billionaire, he's set for life without this stinking president job.
what is the ultimate goal for the Chinese leaders? to maintain the party control.. which can be at risk if GDP stops growing and unemployment shoots up.. it's literally rock and hard place for them because if they give in that means economical colonization with western banks/insurance/financial services go in and kill the locals; or they face an immediate problem of losing the US market... but politicians usually choose the immediate control and push the problem down the road.
look, just a few days ago they almost had a deal.. but backed out perhaps some senior party boss didn't like it.. so Trump plays the tariff card, just to show the determination.
what other choice is there for China? I don't see any.
Or Trump is lying his ass off and the Chinese did not reneg