"Conversions" and other voluntary consumption where people specifically pick the beef they want doesn't really matter to the bigger picture.
Plant based meat is a rounding error until it gets good enough (at an equivalent or better price to ground beef) that McDonalds and Walmart can cut their low end products without anyone noticing or caring. People don't understand just much low end beef sells compared to the mid range products people might replace with plants (at present). In my experience at the foodservice level it's easily 50:1, maybe even 100:1.
It’s ambiguous what you mean by “cut,” but Taco Bell has cut their ground beef with soy based product for years. The biggest question is how far can meat preparations be diluted with fillers... I don’t think we have to eliminate meat to have a meaningful impact (e.g. a 50% reduction in meat consumption would cut about 3% of US greenhouse gas emissions.)
That's exactly what I mean by cut. As the filler gets better (which is certainly the long game for synthetic meats) you can keep upping the amount as long as the end user can't tell. You're very right about diminishing returns and not needing to eliminate meat fully though.
Plant based meat is a rounding error until it gets good enough (at an equivalent or better price to ground beef) that McDonalds and Walmart can cut their low end products without anyone noticing or caring. People don't understand just much low end beef sells compared to the mid range products people might replace with plants (at present). In my experience at the foodservice level it's easily 50:1, maybe even 100:1.