> How long something has been around is often a good way to determine how much longer it will be around in the future.

Might be some correlation there, but probably it's mostly unrelated. We did many things for a super-long time then stopped, because we found something better. For example, we used horses to get around for millennia.

We've done animal agriculture for a long time, but once something better comes around, we'll switch - and food technology is getting very close, and has other benefits too (helps against global warming, etc.).

But just like riding horses, eating animal products will never go away completely, of course.