What is this effect called in After Effects?

Color grading. You could close with Lumetri. Add some 3rd party effects like the color effects from Boris FX, and you are there. Magic Bullet Looks could also get you there. It takes a while to learn, but if you start with Log footage that is 10-bit and work in 32-bit color, you can do some amazing things. 

This is about 30-seconds of work on some cell phone footage I shot to text Rotobrush on the hand on the iPad. You can see the original, the processed footage, and a few of the Lumetri controls I fiddled with. Only Lumetri was used.

It's hard to tell exactly what was done to the TikTok sample you shared, but it looks like saturation, contrast, and detail was jacked up. That's where I would start. 

You also need to make sure that you use the compression settings suggested by the streaming host. Every streaming service recompresses every video you upload to meet their bandwidth requirements, so follow the guidelines. If you upload a video to YouTube that does not meet their specifications, they will recompress it with a sledgehammer. Following the guidelines and their re-compression will produce a much higher quality delivery to the viewer.