A lot of inference providers for open models only accept prepaid payments, and managing multiple of those accounts is kind of cumbersome. I could limit myself to a smaller set of providers, but then I'm probably overpaying by more than the 5.5% fee

If you're only using flagship model providers then openrouter's value add is a lot more limited

The main thing about Openrouter is also that they take 100% of the risk in case of overcharges from the models, you have an actual hard cap.

The minus is that context caching is only moderately working at best, rendering all savings nearly useless.