I don't think depending on Android drivers and having to run a small android just to access said hardware makes it a "linux phone". Especially when the linux experience is compromised because of it.
postmarketOS has no hybris and everything works great, but no device has all the drivers (in fact, no device at all is reported as having a fully functioning camera, let alone everything else) so there isn't a "flagship" device.
If I were to overspend on a linux device I want it to actually run Linux, not a handicapped version of it.
And even then, why stop at the OS? Why is this overpriced "linux" phone not boast having user-friendly and sustainable things like a replaceable battery (probably because it doesn't?). People in this niche don't want just a Linux phone, they want a phone that respects them.