Backpack transport started, so far as I know, when Jesus Jato started hauling pilgrims' bags from Albergue Ave Fenix up to O'Cebreiro, back when there were NO albergues in those 30 uphill kilmeters from Villafranca de Bierzo. It was the toughest day on the camino. He stepped up. It was the only service of its kind in 2001, when I first encountered it.
Soon a few enterprising taxistas carried rucksacks between one albergue and the next over longer stretches, when there was usually only one or two albergues per town, and no other option. Even then, lots of albergues refused to take backpacks sent ahead. Carrying your gear was part of the pilgrim identity. Then came JacoTrans, and a plethora of private albergues, pensions, hotels and hostels that took deliveries. The trail changed. The pilgrims changed, the ethos changed.
Luggage services grew accustomed to dropping off pilgrim parcels where they always did, and it didn't occur to them to offer the albergue any recompense for their providing this service, even if many pilgrims who sent their bags to said albergue had no intention of staying there. So the old albergue, often staffed by volunteers, provided a free luggage drop-off and pick-up service for all the surrounding inns, and dealt with accompanying problems when someone's bag went astray. Nowadays, some luggage services expect to be provided with keys to the albergues, so they can drop off and pick up bags when the hospis are not there.
Lately, many travelers are sending actual wheeled luggage, medical and camera gear, and electronic doodads that require special care and handling... This is not pilgrim gear. So pilgrim-dedicated albergues have decided to get out of the free tourist luggage-guardian business. Bars are picking up the slack.
It's Capitalism in action.