Most people can never be convinced of a vegan diet. I mean, I'm not actually vegan. The lab-grown meats could bring an organic (pun intended) change to society. If it will be available and as good as real meat (and maybe even more affordable), a lot more people could be convinced, thus maybe even opening the door to legislation partially banning farm animals, or enforcing better conditions for them.

It's not good enough that technically people could switch over to vegetables, because most people won't.