like your last line, “solve the problem”, but that requires that a problem be recognized. It seems to me that many do not see this as a problem, but for the OP, for me, and maybe others, it was a problem that deserves attention. It can certainly be challenging to come up with solutions that would be realistic, respectful of the local customs while at the same time addressing the challenges facing the pilgrims. “It’s their country” is accurate, but is that a reason to not attempt to address an issue
You are of course correct: it is a problem that needs addressing.
I think the point being raised by many is that as pilgrims it is
us that should address the problem
not the locals.
It is true that many of us who have responded have either walked a number of camino's and/or have traveled extensively. This means that we are used to addressing these issues, and have long since come up with solutions. Yes, it takes a little extra effort - looking for an open Tienda/ supermarket at the end of the day when all you want to do is sit and put your feet up is not always optimal. Especially when it's raining! Making the effort can however improve our overall experience substantially.
Carrying a couple of long life yogurt drinks and a bag of nuts, a banana and a tin of tuna, cheese etc to supplement our diet adds weight to our rucksacks.
But better to have yoghurt, bananas and tuna than a packet of chocolate biscuits or some cupcakes. Not that I don't enjoy those too: however as you yourself found sweet snacks were frequently available in cafes and vending machines, quality snacks not so often.
This approach is exactly what has happened with wayfinding : you mentioned the arrows. For some, this is not enough, and they still get lost. So others ( not the locals) developed various apps. Problems with finding accommodation? Likewise.
Absolutely, when nothing physically exists then of course that needs to be addressed at a local level. But needs create opportunity and when
sufficient opportunity exists sooner or later somebody will step into fill that gap.