Stagecoach GM makes a handsome 15% margin (proviso here is what it might be be post-Covid) and while its network in GM is pretty good in isolation I am not all convinced that there's a level of reinvestment commensurate with the high margin that's being achieved. As regards the other main objector, Rotala, they are being completely opportunistic. They were all for franchising before they expanded, then suddenly against it post-expansion.
Of course, if you look at the other main operators in Manchester, they are nowhere near that figure. Perhaps it's a reflection that Stagecoach are ruthlessly efficient at managing their business.
As for Rotala, they bought Bolton depot in the belief that it would be a London style, route by route tendering. The London style environment clearly didn't stretch that far and they could lose their business overnight for nothing. If it were your business, I'd suggest you might act similarly?
Regarding on road competition there was a modest amount that could have been removed pre-Covid, eg Oxford Road corridor, but I imagine that case is rather weak now.
The amount of on-road competition now is negligible and was pre-Covid.
My personal view is that an enhanced partnership would have produced most of the benefits for much less cost than franchising. However, to reiterate what I said above Stagecoach were fundamentally opposed to any form of formal partnership (they have form on this elsewhere) and the outline mechanism to force them into one (funding through Bus Back Better) didn't exist at the time that franchising was conceived and formally approved. Had Bus Back Better been tabled a couple of years ago I think things would have moved in the EP direction.
I think in the GM (and Tyne and Wear) instances, it was the case that there was no real appetite from TfGM or Nexus for partnership so the battle lines were already drawn.
My beef with Cornwall is not the network (which was after all planned pre-Covid), but its disastrous implementation. Incidentally, Cornwall is where the first element of Bus Back Better that hasn't been delivered. It stated that the low fares pilot would be introduced this Autumn. There is no sign of that happening.
Whilst the implementation timetable was farcically optimistic (and I think that Go Ahead did a fairly decent job in getting things up and running as best they did), I think you're being overly kind on Cornwall.
If the idea is to fundamentally promote modal shift onto buses, then it isn't served by sending out buses to carry fresh air in areas of low population density. This is the problem with TfL as much as Cornwall with focussing on "hobby horse" services rather than fundamentally moving the needle. Do we want to move more people, genuinely effecting modal change, or do we just want to provide a myriad of "options" to people that have the laudable objective of providing social mobility but can never have more than a barely minimal impact? I keep going back to this but it really needs to be about making the bus (and public transport generally) more attractive as an option - improved reliability of service, more competitive journey times, improved information (both online and roadside)....
People on this forum are passionate about public transport but are also atypical. Most passengers aren't desperate for multi-modal transfer tickets etc - they want a bus that turns up and isn't stuck in traffic. What's Andy Burnham said about bus priority...?