There is also the problem that a lot of times the argument for why it’s better is not framed properly. Plenty Of Studies have shown that if literally everyone were to suddenly go vegetarian we would have the exact same problem just now with vegetables instead of meat. The supply wouldn’t be there things would get ramped up emissions and resource use especially water would increase drastically to try and keep up with the demand.
If you’re going vegetarian just because you don’t like the idea of eating animals then that’s fine, but if you’re at all coming at it from the sustainability perspective then the true solution is a dietary mix that is more heavy towards the vegetarian side of things but still with some meat mixed in just not a dietary staple eating constantly.