They can because they essentially support Google chipsets, which are not blobby like MediaTek or Qualcomm because Google for all its faults is still relatively open (except their recent change in release schedules is why the Pixel 10 series still only has experimental GrapheneOS support).

Here’s an example of the radio firmware and vendor blobs required for a pixel 9 pro XL build: https://github.com/TheMuppets/proprietary_vendor_google_komo...

Nobody, including Graphene, is getting away with building their own modem firmware. The reduced blobs are on userspace and some HAL components.

Do you claim that there's a place where I can find datasheets for peripheral devices for Google Pixel? Like GPU, etc.