Usa had F22 but they still built F35 for aircraft carrier and for airforce, it's multi role plane and alot cheaper to operate. China followed similar path, built a large air superiority J20 and now is building J35 for navy and possible J31 for airforce, a multi role medium plane. They could have already built the J35 but they didn't need it, at the moment they have 3 aircraft carriers but will still need a few more years of training, planning, tactics etc and by that time 2030s J35 and J31 will be ready, Chinese latest submarines will be ready by then, on top their destroyers will be all ready for war.
@MastanKhan always says it can take many years to train your force to be battle ready.