You must have missed the point of the sarcasm dripping from every post in this thread. There is no 7nm speculation. It is so far away from being a reality there is no point in even discussing it.
Case in point: This is the EUV light source used to produce the test wafers that have been ran to start characterizing how the gates actually perform vs models ASML EUV Stepper
Note the throughput given in the article: 100 wafers per hour. That was only very recently reached after almost 20 years of R&D on the light source and 100/hr is their bare minimum for the process to viable even for top-end priced chips.
From Oct 2016 about GloFo and their stepper (same one) GloFo 7nm EUV Progress
Like I said earlier: In another year or 2 if there is an economic need for them and 10nm and lower node mining ASICs are finally produced, of course we'll buy them and of course they will start to displace the current 16/14nm node miners. Until that rather distant future (in Tech Time) is rather pointless to discuss what eventually happens to all devices as its technology evolves.