Arguably carnivores have already cut meat intake, at least red meat, to greater impact than vegetarians.

While I’m going by anecdote rather than data

• vegetarians/vegans are a small minority so limited impact
• many people I know have cut back on at least red meat for health or environmental reasons.

Basically one fewer burger a week by 100 people has more impact than one person not eating meat at all

And that's a more reasonable way of thinking. I tried being a vegetarian and a vegan. Not compatible with my body and factoring in supplements, too expensive.

Thats not how world markets work though. 20% of meat eaters turning vegan would compound vegan movement more than 50% less meat consumed. The former grows vegan market explicitly while the latter just maybe shrinks the meat market only. You have consider availability, research and development, service, pop culture and the fact that we massive overconsume food so less consumption does not directly shrink the market in linear fashion.