If you take into account all journeys you may well be right, if you include car, taxi and bicycle trips as well as those on foot.
But of all current (primarily urban) bus journeys people tend to use them primarily for direct trips and another mode for ones where a change of bus would be required - usually that change (given that timetables rarely line up) makes bus such a slow option that even cycling (and sometimes even walking) wins time-wise, particularly if an e-bike is an option. In this sort of situation people wouldn't generally go by bus if they were paid £2 to do so.
Thus I'd stick to my view here - most bus journeys will be return trips on a direct bus into the nearest urban centre. There may be a difference in London where frequencies are very high though, but it would be interesting to see (though I doubt TfL publish) how many Hopper fares are actually used each day as against simple single journeys.