It should be patently obvious to anyone with an IQ exceeding that of Winnie the Pooh, that if the services are profitable (to the extent they require), other operators will step in, and if they're not, then subsidy or abandonment will follow.
Now - that opens a can of worms regarding 'profitable'. Is a bus "service" there to serve, or to make money? Can a company make money where another can't by cutting costs (i.e. negotiating a better fuel price, "efficiency savings", lower pay / conditions for staff etc)? Do some compamies demand a better return than others? e.g. Group A is satisfied with a 6% return, another (B) demands 10%, and the service(s) produces 8% - so "B" says it's unprofitable and "A" takes it on.
The bottom line is that unless frequencies and reliability is up to potential customers' expectations, usage will dwindle beyond the tipping point. "Don't wait for the bus - I'll drive you there. You can have the temperature/music/departure time as you wish, you don't have to stand in the cold waiting, the pot-smoking youths won't be there to bother you, I'll wait for you on a yellow line and b*gger anyone else ... 101 other reasons...
Add to that the various Councils' planning policies - lots of new houses with no local amenities, make it easy to drive, provide parking, ban buses from town/city centres, and you have the perfect storm.
40-50 years ago, the whole area was covered by Crosville. Some services made money, some not. It wasn't perfect, but in those days, as a whole, the network worked to provide the needs of the majority of people at reasonable fares.
Now, the bean-counters who run operations know diddly-squat about any of this, but look only at their bottom line of 'If we close this depot, will I still have a job".