This will stand or fall based on the LA's ability to understand how people use buses. If they can't do that, they're unlikely to be able to use buses, drivers and information/technology any more efficiently than Stagecoach or an independent who have operated commercially in this area for nearly 40 years.
So the only financial benefit will be what little is saved by not having to meet Stagecoach's profit margin and not running duplicate services. I'd guesstimate the LA is probably already going to be spending more money designing, tendering and monitoring a franchised network than is saved.
So that only leaves benefits like cheaper integrated ticketing with rail, better accountability to bus passengers and the single network brand/point of use. I suspect none of that is going to drastically change the lives of bus users in Cambridge, whose primary concerns are reliability, affordability and convenience. Just like every single other bus user in Britian. But for some reason we're spending millions on consultants to keep finding that out, area by area.
I personally think given Cambridge's history, the only reason they want franchising is so they can force buses to use expensively procured infrastructure like a busway, bus lanes or park and rides. And unlike enhanced partnerships, which offer that same benefit and some of the others, with franchising it's easier to hide the fact buses are being run inefficiently or even ineffectively.
In places like Cambridgeshire specifically, franchising merely allows the LA to better illustrate with hard data that the main obstacles to better bus services, ones that keep to time, don't cost too much and go where people want to go and in a reasonable time to get there, is traffic congestion and the allocation of road space.
So I'd say the only long term goal of bus franchising in Cambridgeshire is to build local political support and pressure on the DfT/DoE for this area to emulate it's friend and rival Oxford and become one of if not the most hostile place for car owners. Severe restrictions on where you can drive, and severe financial penalties on not just where you can park, but the provision of parking itself.
Not necessarily restrictions on car driving, since you can foresee a future where the LA runs a whole gamut of services, from bus rapid transport, urban and suburban conventional bus services, rural and hyperlocal demand responsive minubus transport, and autonomous car share schemes.
As always, the benefits of such things stand or fall on the competency and capability of local politicians and civil servants. And to be honest, when the busway was being mooted, I doubt even the most ardent supporters could have foreseen just how badly it went. Similarly the Edinburgh Tram. Poor risk/project management. Poor design. Poor construction. Massive cost and embarrassment on the backend.
So perhaps rather than consulting on what, they should be consulting on who and why. Notice should be taken of all the research that has already been done into how and why such things never seem to go to plan. But the plans are always fantastic, stuff nobody in their right mind would ever say no to when they're asked if they think it's a good idea.