>it's a different layer of infrastructure, but it's still infrastructure.

TikTok isn't "infrastructure", TikTok is software. TikTok exploits the infrastructure of the internet across the world, it is not infrastructure itself. The servers TikTok runs on is technically "infrastrucutre", but those same servers could run anything else, the hardware is not "TikTok". I could run "TikTok" the software on any hardware, even if it isn't connected to the public internet, and that would not qualify it as "infrastructure", at least not in the sense that it's servicing any population.