The population of the villages that have been mentioned has been divided by two or three between the 1930's and the 1990's, when it got to its lowest. As of lately, it mostly stagnates.
I agree that, when there's nothing, buses are better, but dismantling existing rail infrastructure and then adding buses is certainly worse. Especially when the bus service is so shitty. Electric trams back in the day moved so slow because they didn't have the technology to get a nice 80 km/h (or even 100 km/h) cruising speed they could use nowadays. Now everyone has to use a car or perish. I'm confident a large part of the demise of the area, aside from the loss of rural jobs due to industrialisation, was the fact that the infrastructure worsened so much. Not only rural trams closed, but small retail stores as well. To live as comfortably as in a city, you need to drive at least 50 or 70 km a week, and that's assuming you plan your purchases very well and don't have emergencies. If you have to commute with your car, make it 200 km. And when the rural exodus happened, cars were very expensive, an upper middle class item that you certainly couldn't afford with a blue collar wage.>>1262463
I can only speak for France, but basically, departments (administrative levels below the region) had the authority to declare that a train line was of local interest, and then it was built and exploited by a particular company. In the case of OP, it was the Society of Electric Trams of Ariège that built it in 1907, extended in 1911, and with further branches planned, but never built, for nearby valleys. The Great War thwarted those plans, and in the 1930's, owing to the economic crisis, the apparition of cars and buses, and the accelerating depletion of rural areas, they closed down.