Most of the Chinese manhua are fan-made quality webtoon published on platform like kuaikan, qq or weibo. The quality is variant unlike those 1-pick-out-of-50-quality paper printed Japanese manga. Curiously, some popular manhua are actually quite bad (usually shounen type). There are fierce competition between platforms, so they sign exclusive contract with some authors. When the contract ends, the authors need to make decisions. They probably decided to stopped and made them free on qq platform.