Health wise there really isn't a big advantage to being vegan, vegetarian, or a meat eater. People can have healthy or unhealthy diets regardless of particular restrictions. In the past there wasn't a lot of vegan junk food or options so vegans kinda had to be healthy on accident. Now days you can get just as messed up on vegan food. As an example oreos are vegan but no one is going to argue they're a healthy meal.

A complete protein is important but a little more complex to get without meat or dairy. Right now the cheapest protein sources are chicken or protein powder derived from milk (whey). Vegan options are kinda pricey for powder and whole foods would be kinda a pain if you want a higher protein diet. I wonder if they could do "lab grown" complete protein powder cheap.

Arguably the lab grown meat could be more efficient than growing a whole chicken. And a lot of people simply won't give up meat.