The big industrial brewers want efficiency and speed.
Natural fermentation in the bottle takes extra handling, storage space (Lager means “to store” in German) and time. Beer will will taste pretty green for at least a couple weeks while the little yeasties do their thing. This continues for a long time, I’ve naturally carbonated beers that are over a year old and they taste fantastic.
Comtamination with outside yeasts or bacteria, or overdosing on the “priming” means exploding bottles, too. I can see where Beer makers and vendors don’t want to mess with that. At all.
Yes, but I see Belgian, Czech and German beer makers follow only the natural method and their beers are so much better