Clearly, it's GPU's for you

Most here would argue two Vega's is a waste, but that's whats important to you. Think about that when you tell others that their choices are bad.
Sure.
I'm not defending purchasing 2x GPUs.
However... since you brought it up...
Yes, buying them was crazy perhaps (for an outside observer). But...
My old RX480 (since donated to my girlfriend's gaming PC) paid for itself and then paid for the first Vega via mining. The mining profits went nuts, and then my first vega plus the remainder of the RX480 profits paid for the second Vega.
The pair of Vegas since made me a bit of money.
So really, in my particular case, i basically got the pair of Vegas (and also my old RX480) for FREE once the mining profits are taken into account.
Wanting to buy the new phone because its your thing doesn't mean it is an objectively good idea.
At least my cards paid for themselves (And then some). Your shiny new iphone replacing last year's model will not.
Additionally, when i bought both Vegas, i got it them at very close to RRP, while they were on ebay for 50% more. I could still sell it for almost what i paid for it.
I'm not trying to tell people what to do with their money. I will however point out that going straight from one model to the next is a crazy waste of money. If you want to do it, go for it. Doesn't mean it makes sense though.