One hundred years on we are in the same position as we were 101 years ago no buss service between Maidenhead and Reading .....................
For 2 reasons the train is faster and the automobile

But the train does not stop every 500m or so (at least not in the TT!) and so cannot serve a myriad small communities. A convenient bus can still be attractive, even to car owners, facing ^1.80/hr parking.
An hourly bus running even alongside a railway has only a tiny fraction of the capacity of a train. It is therefore nearly always complementary and can only hurt a poorly used train service.
The A4 between Maidenhead and Reading now by-passes the larger villages and so probably doesn't merit a regular bus, just like the A33 Reading to Basingstoke. A pity if you want to use the buses as a network but there are excellent Reading bus services to other
TV▸ towns.
OTC