That's a strong claim for not looking into it at all.
From a brief glance at the white paper it looks like they are using TEE, which would mean that the root of trust is the hardware chip vendor (e.g. Intel). Then, it is possible for confidentiality guarantees to work if you can trust the vendor of the software that is running. That's the whole purpose of TEE.
I guess you're unaware that Intel TEE does not provide physical protection. Literally out of scope, at least per runZero CEO (which I didn't verify). But anyway, in scope or not, it doesn't succeed at it.
And I mean I get it. As a not-hardware-manufacturer, they have to have a root of trust they build upon. I gather that no one undertakes something like this without very, very, very high competence and that their part of the stack _is_ secure. But it's built on sand.
I mean it's fine. Everything around us is built that way. Who among us uses a Raptor Talus II and has x-ray'd the PCB? The difference is they are making an overly strong claim.
Everyone likes to dunk on the US, but I doubt you could provide a single example of a country that is certainly a better alternative (to be clear I believe many of the west up in the same boat).
From a brief glance at the white paper it looks like they are using TEE, which would mean that the root of trust is the hardware chip vendor (e.g. Intel). Then, it is possible for confidentiality guarantees to work if you can trust the vendor of the software that is running. That's the whole purpose of TEE.