Not talking about meat vs vegetables being better or not but do you think that vegetables aren't factory produced? Do you think that fruits and vegetables aren't picked before fresh and sprayed with chemicals to make them the 'right' color or slow ripening or keep them from spoiling? There is also the often un-talked about issue of calorie density by weight or volume. All these things need shipped from where they are grown to your store/house. Meat is generally 10 times more calorie dense. So to ship the same calories we would need 10 times the trucks which would have a huge CO2 implication. Fruits and vegetables have tons of fiber and water which are good for us but it costs to ship them. The only way to make fruits and vegetables more weight/volume dense and reduce the fiber would be to blend them up into something akin to a smoothie. But then this will require more chemicals to keep it fresh. Also, I don't want to eat all my vegetables as a liquid so....

In the end, there are hugely interconnected issues and most people take one small facet, extrapolate it to infinity and ignore all the ripple effects and consequences of even the smallest change.