There is an assumption everyone has or wants a phone, also an assumption that people can afford a phone, or data (even with data gifting) so as a result more services are using phones,
At the same time, as you said we can't use cash on buses (we can where I am) however all these require smartphones, which we want to ban for under 16s, so they are going to find them selves in that precise situation.
We also assume people have phones running Apple or Google so what about people using other things like postmarketOS, graphine, which as far as I understand are open sourcee, mobile systems, unless they are compatible with google android.
I agree people need to wake up or we are going to just be excluded.