The most fun and clever Instagram and Snapchat filters come from the community, not the company. The company needs to find ways to unlock the creativity of the community.
The second wave of social is about having people be more conscious about building a graph that best matches the needs of what they want to get from that graph. Initially, importing from your contact/address book made sense. But now we can say that was a mistake. You don't need to follow all people you know on all services.
Facebook is context collapse - the social graph includes so many people. TikTok's social graph isn't built on a graph of people you know which avoids the context collapse.
We'll look back at social graphs and say that it is a mistake to use the social graph to approximate an interest graph. The people you now don't necessarily reflect your interests.
Most of the work on TikTok is derivative of other work. Whether it's dance, music, or some other work. The majority is a remix of someone else's work. That in itself is very different from other social networks. Instagram doesn't have a reshare function by design.
On YouTube there is no editor. You can't create content, you upload it. They are a default CDN for video content, so not sure if it makes sense or they could ship something superior to other editors.