There will be cheaper Motorola devices with GrapheneOS support too. It's initially going to be limited to flagships due to Qualcomm not yet having MTE for a non-flagship SoC. A flagship SoC is easily more expensive than a lot of low-end phones. Pixels have a much easier time providing high security and long term updates for the budget 'a' series line because they have an in-house SoC used across their devices. Pixels also have no flagship SoC with competitive performance despite selling flagship devices using the same SoC as the lower end devices. It has drastically lower performance than a Snapdragon flagship to the point that the flagship Snapdragon will be an upgrade of ~60% to single threaded performance, ~80% to multithreaded and over 100% for GPU performance.
Just curious, how relevant is MTE when considered a security feature? IIRC, last time i checked there were reports about extracting tag values so that maybe the access control enforced by the tags can be bypassed.
MTE is very important because its a measure against an entire, very important class of vulnerabilities, memory safety vulnerabilities.
Generations of MTE improve over time. The implementation of MTE used on a Pixel 8 for example has certain side channels which arent present in the MTE used on an iPhone 17. That being said, it being imperfect doesn't make it irrelevant.