I suspect it's the features of the titan m2 security chip. It's a pretty cool piece engineering [0].
[0] https://www.androidauthority.com/titan-m2-google-3261547/
GrapheneOS is actively working with a non-Google Android OEM towards their devices officially supported GrapheneOS and it's certainly something we're interested in providing. Existing non-Pixel devices with proper support for using another OS don't meet our hardware security and update requirements.
As a side note, GrapheneOS has always avoided using the term ROM to refer to any Android-based OS. They're not actually ROMs and it leads to misconceptions.
Samsung Flagships and Iphones seem to have similar level of security engineering in them (Pixels use Samsung CPUs essentially) but aren't open to the required degree for third party roms.
There's nothing else on the Market that delivers on that Level. The GrapheneOS guys are working with someone one a potential custom phone to get the required level of hardware security but nothing has materialized. Companies like Fairphone are free to deliver hardware that is competitive in the security space and i'm sure that the grapheneos team will consider them then. But until anyone else does i'll keep buying whatever phone grapheneos wants me to buy, i don't care.
Samsung has devices providing all of the major security features listed at https://grapheneos.org/faq#future-devices and they could easily add the couple things they may be missing such as reset attack protection. The issue is that they don't allow another OS to use a bunch of the hardware-based security features.
Samsung devices aren't on the same level as Pixels in terms of quality of implementation for security, but they would meet our security feature requirements if they let us use the security features.
Whether Samsung's security update approach meets our requirements is a different story. They do provide long term support but it isn't necessarily what we expect. There are often long delays even from the beginning and they tend to switch to doing the security updates with months in between for older devices. Huge delays for yearly updates and not shipping the monthly/quarterly updates is an issue too since we'd be running a newer OS version on top of components from an older one, relying on Treble for compatibility, which is likely to cause issues and therefore delays. We can accept having to use Treble that way but it would be significantly harder to provide the OS updates as quickly as we expect.
As a side note, GrapheneOS has always avoided using the term ROM to refer to any Android-based OS. They're not actually ROMs and it leads to misconceptions.
> The GrapheneOS guys are working with someone one a potential custom phone to get the required level of hardware security but nothing has materialized.
The current OEM we're working with started working with us in June 2025 so it hasn't been a long time. The previous OEM went bankrupt, but this is a larger and more established company.
Thanks for giving me a freedom respecting alternative to Google and Apples duopoly.