Snapchat is a very different use-case. Snapchat was built on being a sort of anti-social-media. It's all about ephemeral content, and not making it easy for content to be shared widely. TikTok has a lot more going for it in terms of intrinsic properties built around bringing more users into the platform. Snapchat is about having a more low-pressure online presence, TikTok is a "look at me" platform.

TikTok is a lot more analogous to Instagram: where Instagram used filters to allow normal people to create much more appealing photos, TikTok's music licensing allows average users to create videos with a much stronger emotional appeal than they can get on other platforms.