I don't see what the problem is, imo it is a specific question. Almost no apps access the home wifi network, they connect to a remote server on the wan side of the network going directly through the default gateway/router, knowing nothing of the devices in the lan.
Who's going to pay for that? Not only the software, but the video hosting, transcoding, etc.
And don't tell me you can do it with p2p - the entire point of tiktok is that you can load new videos by swiping your finger. If every video takes 10 seconds to begin buffering nobody will want to use your app.
I signed up to the Bing GPT "beta" waitlist (I hadn't logged into my Microsoft account in years) only to be told, days later, that I had to use Edge to try it. I noped out of there.
