Maybe but in the early 1800s there was a guy similarly saying “The idea that people would voluntarily stop enslaving people and switch to paying wages is just wishful thinking” and yet we seemed to have changed that one.
Not saying that it was 100% economic and moral/ethical awakening didn't play an important role, but the economic changes definitely helped. And this kind of favorable factors aren't apparent in the case of convincing everyone to go vegetarian.
and I wouldn't compare slavery to meat consumption.
Marjorie Spiegal wrote about it in length in her book "The Dreaded Comparison"
https://archive.org/details/dreadedcompariso0000spie_o7y4/pa...
You can attempt to argue for the merits of the comparison, in your own words, if you'd like.