For clarity from the government website
It’s illegal to use your phone while driving or riding a motorcycle unless you have hands-free access, such as:
a bluetooth headset
voice command
a dashboard holder
The law still applies to you if you’re:
stopped at traffic lights
queuing in traffic
supervising a learner driver
they are talking about hand held devices if mounted/hands free etc then you need to be seen as out of control.
Otherwise they would not be allowed to sell vehicles here with steering wheel mounted controls and have them active when on the move.