Reddit's search engine is notoriously awful, if I wanted to find something on Reddit I would Google it with site:reddit.com in the query, that gets great results.
As for Tik Tok, isn't that a short video site? Its very popular and clearly good at what it does, but how can I search it for a Wikipedia article, or a rotten tomatoes review of a film I'm interested in, or bus timetables, or opening times for a local store, or helpful coding solutions, or wiring diagrams for circuits, or converting values or translating text, or any of the many, many more things I use Google for every day.
On a personal note, while I've sold my soul to one or two major western corporations, I'm never going to willingly provide the Chinese government with any more information about me than it may already have. Certainly not about to start directly informing them of my searching or video watching habits.
Nor will I ever support their genocides and many other human rights violations and evil cruelties if I can avoid it. Tik Tok isn't just some hip new app that's cool to use, it's an evil fascist government's tool for surveillance and control.
Crazy thing is, I'm not even a conspiracy nut, I'm just citing a well known fact, and yet people keep using it anyway because they just don't care :-(