I'm not sure that the tackle shop theory holds that much water. There are fewer in town tackle shops since the rise of commercials and the attached tackle shops. The tackle shops associated with commies are certainly better than nothing, but they are invariably a waste of time for an angler fishing rivers and more natural stillwaters. Those in my neck of the woods don't even seem to be capable of keeping decent quality maggots, let alone turning quality casters that the river lads demand. When it comes to terminal tackle and rods more suited to a river, you can pretty much forget it. As far as I'm concerned, the in town tackle shops are fewer largely because of a change in shopping habits. However, the on site fishery tackle shops and the reduction in anglers using maggots and caster have also impacted on them.
Fortunately, the few local in town shops left still cater for the relatively healthy numbers of river (and river match) anglers that are still active. They carry rods and terminal tackle that would be all but useless on a commie. Most importantly, they haven't forgotten how to keep fresh bait. It's perhaps not surprising that newer shops, or those associated with commie fisheries, tend not to stock quality fresh baits. When the bulk of your bait sales consist of pellets and you have little or no experience of keeping quality maggots, they probably don't care.
Commies have their place and there's patently a demand for them. However, I'm not remotely convinced that they are the saviour of the tackle trade, and angling in general, that some claim them to be. That's similar to claiming McDonalds as being the saviour of the restaurant trade.
As far as travel goes, I have to drive further than two decent rivers (Swale and Tees) and my stillwater syndicate to get to anything particularly worthy of the "commie" name. Whilst I'd not be particularly keen for the rivers to get too busy, I actually wish that they were a lot busier than they are now. The clubs concerned would be in a far better position and the rivers actually fished better with more anglers putting bait in. In most instances, the busy stretches of river are caught in a self fulfilling prophecy. Until a certain tipping point, the more anglers that visit, the better the results are. It's vice versa for the deathly quiet stretches. Whatever fish that are present get harder to catch because they see so little bait. It's also worth noting that the busiest stretches of river I know locally are those that are little more than a fifty yard walk or where a vehicle can be parked behind the peg. It's also interesting that these places invariably end up being considered as the most prolific stretches on the river.
Sadly, it seems that many anglers that frequent commies tend to fish them exclusively. The prospect of walking any distance, not having a level peg, or having to work too hard for a minimal number, often of smaller fish, doesn't appeal. Even for those that aren't past such exertions, I can understand why, especially when they are only occasional anglers. I wouldn't turn my nose up at the prospect of being able to walk no more than fifty yards on a river, to a nice level spot with a swim pretty much the same as all the rest and a pretty good chance that I'd catch a few, including something half decent size, wherever I chose to stop. It's a lot better prospect than getting to know the stretch intimately over a long period of time, watching weather conditions, river levels, temperatures etc, and picking your times accordingly. Even then, the only thing I can almost guarantee to catch is a load of minnows. Believe me, I understand.
Far from being the saviour of angling and the tackle trade, I'm of the belief that commies have been pretty dismal for the wider tackle trade and general coarse angling. The only thing that they've been especially good for is themselves and the anglers that choose to fish them ahead of any other type of venue. If and when angler numbers rise significantly (Covid upturn notwithstanding) and tackle shops stop closing at a rate of knots, I may start to believe that commies genuinely are to the greater benefit of anything but themselves.