How does franchising buses tackle the issues of unreliability caused by congestion, streetworks etc, the shortage of drivers and the ability of any ability of local authorities to support services from already stretched budgets?
On the assumption that you want a bus service that's reliable, and takes people where they [want/need] to go when the [want/need] to go, these issues you list are amongst those that much be tacked by any system. That whether you have buses run in-house by a governmental authority, run under franchises operated by a local authority, running commercially under a regulated system, or as a free-for-all where anyone can just buy a bus and carry passengers.