And what about those who use a phone mounted on their bars as a navigation/stats device. Does that count as "using" a mobile phone.
And many GPSs, Garmins and Wahoos are bluetoothed to mobiles so are they an extension of the phone? (as in your "dismiss a call alert" example)
It's utter bollocks.
Caveat - not, of course that I think actually using the phone for comms - texting or talking - is actually a good idea. On the contrary. But is it a real nationwide problem in need of addressing? Of course it isn't this is just someone looking around for pointless regulations to throw at cyclists.
Quiet road, I might very occasionally whip out the phone for a photo without stopping for it.
It's even illegal to stop on the carriageway here - the A82, as it's a clearway:
So the only legal way for me to get that photo was to take it while moving!
Whereas this one on the A9 I just didn't want to have to push off again while climbing Helmsdale.
In all instances, there was nobody else around. This risk to other people was demonstrably zero. And I'm comfortable enough in my bike handling to be riding one handed for a couple of seconds (I don't even have to
look at the phone to take a photo).
On the other hand, riding no handed down a pavement while texting, as I do see happen occasionally, is obviously stupid and dangerous. But that's already an offence - careless/dangerous.