Are artificial ingredients better than natural ones because they are made in laboratory conditions?
The question is by no means restricted to vanilla. It refers to any natural product that can be reproduced artificially. Ditto for the answer.

Sure, the artificial product might have the right chemical formula. Also, it can be made as pure as you want. The problem is that the natural product is not pure. It is a bunch of various compounds, and they all contribute to our perception of the flavour. You identify the compound that makes up 90%, investigate its structure, develop the synthetic route, and finally you hold it in your hands, and it feels just about right, but something is amiss. So you look for the next component, which constitutes 9% and hence is a lot harder to isolate, and after a long and tedious procedure you identify it, and repeat everything, and finally you end up with the product that feels totally right. Well, almost so. Is it the remaining 1% that is responsible for the difference? You never know until you try.

So it goes.