You'll probably change your mind. If/when synthmeat becomes both economical and palatable, it will rapidly become socially unacceptable to eat real meat.
All that needs to happen is for the synthetic meat to test better than regular meat.
If there are two products, one being the original and the other being artificial, I assume there will always be a market for the original. It'll just lead to a price increase.
As it is, whey doesn't have the right flavors and cookability, tofu doesn't have the same flavors and has a lot of carbohydrates, and mushrooms don't have any protein in them.