OpenRouter is basically a payment system for LLM tokens. Yes, it does route TCP connections from you to an inference providers' cloud, too, but what is way more important is that it routes money from your wallet to inference providers'wallets.

The latter is the core business of Stripe. For them, buying OpenRouter to become the premier channel for LLM token money makes perfect sense. At least if you assume that the current state of labs offering heavily subsidized subscriptions directly is only temporary and the future lies in people buying tokens and switching between models fluidly - and I consider that the future, in light of the recent developments with Kimi K3.