It does seem a bit pointless. Maybe the hand to mouth thing helps a little.
I only knew one person who followed that path except he didn't bother with lowering the nic level. One of the bosses at the last place I worked. He got quite a nice setup, big mod and tank. He pledged to use it for 6 months and then dump it. He did quit the smokes and then trash his vape gear after 6 months. I retired soon after that so I don't know if he succeeded in staying off the smokes.