Only medications or hormonal changes will increase hair growth, waxing doesn’t. Also shaving doesn’t increase the hair growth. It just seems that way, because instead of hair with a soft, relatively thin hair end, there will always be a (thick and blunt) stubble present.

So if you have shaved or waxed your legs when you were a teenager, and you subsequently have more hair, this is not a consequence of shaving or waxing, but of hormonal changes. You would have got those extra hairs anyway, even if you had not shaved or waxed.