Most people may be unaware that Garmin has a strong foothold in the stringently regulated avionics industry, in particular in flight instruments, displays, deck and others human-machine interface products. In turn, specific regulations informed by ergonomics research are unambiguous in prioritizing safety and unanimously contain minimum usability requirements.

As an example, an AC [1, Ch. 7] advises on (electronic display) control devices, and another AC [2] advises on design and evaluation of controls and displays. The software-defined counterparts have immensely harder requirements that must be satisfied, which, in my reading, is incompatible with pure touchscreen devices.

[1] https://www.faa.gov/documentlibrary/media/advisory_circular/...

[2] https://www.faa.gov/documentlibrary/media/advisory_circular/...