Also anyone with access to an LLM and half a brain can spin up a website.
It's the frictionless onboarding, simple UX and dopamine inducing content that enables those 3 companies rule the internet.
And yes, that's why we don't need to act like they're somehow important. They are not. They are not the Internet. They don't even contribute toward the "useful" part of the Internet.
These are not sites where people "find essential information, build community, and weigh in on public discourse." They're not some classical forum where the adults hold important debates. These are sites that present a highly distorted view of reality to each individual so they can keep them engaged to feed them more propaganda. That and gambling/porn.