OpenRouter is the evidence that yes. Its just that the idea is dumb. What you are seeing in VCs salving their own money, buying their investment out with the money they out into more successful ventures.
Look at how the same pools of capital sit on multiple sides of the market: the router, the payment layer, and the model providers... Its all the same club
You definitely can build an LLM router with only the features you need (even the ones absent in OR!) for cheaper. Openrouter is 5% markup on all token usage. If you're a serious pay-per-use customer of AI, that's a lot of money.
What mindshare? It literally is an API gateway with a rather minuscule usage that anyone can drop at any moment to use any other proxy or when providers forbid the use of their services via proxies (like it happened with Anthropic already).
How the hell can it be anywhere close to $7 billion?
When Facebook bought Instagram for $1 billion, it had 30 million users with hardly anyone else competing in the space.
I can still use Claude via openrouter. Anthropic blocked using your Claude code subscription via other harnesses but you can still use pay as you go API billing.
Ignoring that you can't reproduce the widespread adoption and mindshare OpenRouter has already built.
That's what Stripe is spending $7 billion on.