Mendip Explorer started out boldly, then gradually fell apart. First the 171 (Peasedown) and 175 (Shepton) shorts went and more recently Paulton is now lumbered with the abysmally unreliable 379 service rather than the previous 171 and 172 circuits. I think it could be reasonably expected that either 172 or 173 will disappear when the network is next reviewed, to return Midsomer Norton - Bath corridor back to the 20 minute frequency that it was at the turn of the millenium, pending the Combined Authority throwing BSIP money at them for a couple of years to run oddly numbered services which miss out most target destinations.
The Discover network similarly started in a blaze of publicity then gradually fell to bits, to render it less effective than the services it replaced.
North Somerset's network went through being Travelwest, then Excel and now Badgerline. Despite the local authority spending plenty of money on it from various pots of money, none of the marginal services have ever become any more sustainable and now much has been withdrawn.
Clearly none of these projects has delivered the passenger usage growth required, perhaps because of a lack of effort beyond painting some buses and changing route numbers, perhaps for other reasons. I therefore maintain my skeptical position regarding the oft quoted statistic that the operation (and region) had strong year on year passenger growth prior to Covid, because the continual degradation of services outside of Bristol doesn't support this. I remain of the opinion that this growth if it did exist was solely down to student usage.
I do agree with much of what you say though I just don't know whether the claimed 7 million extra journeys can all be put down to student travel.
As you know, I thought the recent changes to the Mendip Explorer are ill-conceived. The 379 running as part of the Norton Radstock to Bath corridor was disastrous in terms of service reliability when tried before. To do it again and expect a different result is the definition of madness. I fear that you may well be right in your prediction with the 172. The lack of printed timetable/publicity for ME routes when there is a significant tourist market seems very short-sighted. The 376 now has a cockeyed non-clockface timetable. It feels like it's being done for operational convenience more than a strategic objective in even arresting decline, let alone growth. The vehicles are now aging and looking down at heel, internally and externally. Yet when it was originally ME relaunched in 2016, they did do a decent job - there were the new Streetdecks, the Eclipses (and later the 5 Geminis) were refurbished and gained USBs, there was extensive internal promotion on the vehicles, plus other promo stuff in places like Wells. Think it is fair to say that they did generate passenger growth. On my local routes from MSN to Bath, it was rare to see a full Eclipse/Dart heading to Bath whereas, at least anecdotally, the need for deckers seemed genuine.
As for the North Somerset routes, the early moves were promising. The Express Yourself era seemed sensible enough and First was emboldened enough to put the new Streetlites on the Portishead routes. However, even in those days, we had the A2 and its ever-changing route and role. Moving to Excel seemed a rather pointless move, and yes, absolutely agree on the myriad of route changes, renumberings, the hoovering up various bits of funding etc. First was clearly culpable in that though they were involved with North Somerset Council, who is one of the most lacklustre local authorities I can think of. Where Express Yourself had good roadside publicity, including bus shelter advertising, NSC seems to have decided that they happy to take the money from external advertisers - seem to recall one bus stop near Pill that has had full advertising for new housing, some sort of eco electricity firm, an estate agent, and now a fire alarm business! Mind you, bus stop maintenance is appalling throughout the area with Covid notices and references to Crosville still widespread in Weston.
At this point, a return to the 126. Having actually not having done much (except a back and forth swapping of one board between depots), there was to be the Strawberry to rejuvenate that route. Then Covid intervened. Then to keep it, cut the 173 but then restore that and axe the 126 instead (if that is what happened?). Enter NSC and Somerset Council and an ability to really cock things up with any pretence at a sensible solution being sacrificed on the altar of respective boundaries. In that respect, at least Somerset did something in contrast to NSC's ridiculous ignorance of the problem in any sense.
Discover is an interesting one. A rather bold expansion against Faresaver on the Frome and Melksham routes so that they had 3 buses per hour (two First, one Faresaver) on routes that even back in the day were only hourly. I guess it really does emphasise that wheeling in Ray Stenning is not a guarantee of success! They did put in new bus stop flags (in some places but not others - some changed in Hinton Charterhouse but others not and I don't know why) and the vehicles were smartened up and the leaflets/publicity were good but again, it wasn't long before there was some fiddling. Was the hourly Salisbury extension reduced to two hourly in a year? Melksham was surrendered just before the first Covid lockdown. What odds that the Discover brand will be dropped in favour of standard Bath City blue, again for operational convenience more than any other reason? How the D1 isn't viable on an hourly frequency between Bath and Trowbridge, I just struggle to see. The closure of Westbury outstation was also a poor decision in my eyes, if only for contributing to further challenges in staff recruitment in Bath!
To my mind, there was constant fiddling and tweaking going on and to what end? It seemed to be a struggle to find some magic solution. I mentioned the 19 and the 37 but the X6/X7 were also prone to this. Same with the 179 that experienced the death of a thousand cuts.
With First now in decline management mode in West of England with Doug at the helm, luke warm local authorities, and West of England Authority and their hobby horses, it really compounds the wider problems locally that are seen nationwide.