I'm not part of Oxide, but I think you're assuming everyone is okay with not controlling the hardware they run on.

There is plenty of addressable market where a public cloud or even a colocation of hardware doesn't make sense for whatever bespoke reason.

I don't think their target customer is startups, and that's okay. You likely aren't their target customer. But they've identified a customer profile, and want to provide a hardware + software experience that hasn't been available to that customer before.