Bilibili is a minority player in China, so it's pretty weird to present then as "China's answer to YouTube". I'm pretty sure the biggest video platforms are still iQiyi, Tencent video and Youku (with none of them having a dominant position like Youtube).
Surely Bilibili is actually the answer to "where can I watch anime and mingle with others in the 2D subculture", a market which YouTube doesn't seem similarly interested in. (YouTube has the subculture, but AFAIK no licensing deals with Japanese studios. If they do have licensed content for paying customers, they're not advertising them very well.)