Do engines help in OTB to the core level?

Hello. Imagine a player, a bad player (on chess.com), whose sole goal is to get better (as it should). However, imagine he does not want to play others, because he only wants to show his "best side" to the world. So what does he do? He plays engines. On live, he works his way up, from Computer1 to Computer5 to even higher levels. Assuming he achieves this, and gets a good rating purely off engines, he goes on to play actual people? Would his rating mean anything? He earned his way to 1400-1600 purely off engines, so when he decides to play OTB, how would his rating react? Would it skyrocket because engines play the "best" moves but humans can't calculate that good? Would it plummet because he's used to engine play and he can't cope with the different style of others? Or would it stay, either because both these effects would cancel out or because it keeps fluctuating (so his average is same). This brings me to a broader question - even if engines help, by how much? How much can we rely on them purely to get from 100-1600? Will they honestly help in OTB, when all youv'e done is play engines, and not a single human? And on a broader sense, do engines even help??

Sole goal or soul goal? Either way, are we not allowed multiple chess goals? Surely we are. 

Use engines to try to help you understand chess moves, and, of course, for playing out some positions. But everything should be geared towards increasing your chess awareness and your understanding, engines just being a tool to assist on those paths.