Because it (anecdotally) crashes too much, but only on $$$ devices with cool CPUs that can use it. People buy expensive phones because they're supposed to work better.

They should really do some sort of sampling thing to generate crash dumps and find big offenders and increase the coverage over time.

For Google employee devices, 0.1% of background execution starts while charging in an idle period (overnight bedtime charging) will use MTE. When any specific device hits an MTE crash, back-off sampling for 1 week on that device. Modulate the sampling rate so crashes are manageable.

When Google employee devices are not crashing overnight at a high rate, then start sampling background execution during the day for employees and overnight background execution on general user devices. Finally, sample on foreground execution, again for Google employee devices first.

If there's significant variation in crashes by app, you probably need to setup a way to set sampling rates to zero or very low for application versions that have been identified as a known problem and don't need additional traces.