> more would choose vegan than if it wasn't more expensive.

If?

Getting protein from vegan sources can already be done much more cheaply than getting it from steak, though the quality of the amino acid profile may be lower.

Getting protein from "the vegan option to a steak" - i.e. something marketed to be a direct substitute for a steak, with its vegan nature as an explicit selling point - is a different story.

I presume that, generally, people eat steak because they subjectively enjoy the experience of eating steak, and perhaps because they don't enjoy a carefully planned out plate of legumes and whole grains in the same way. But some seem to be much more extreme about this than others.

I personally eat meat (and dairy) regularly - but probably overall less than the local average, and usually not beef.