Miners will go away someday when bitcoin reached its maximum supply and there will be no more popular POW coin like bitcoin. The miners have no choice other than migrate into another POW coin.
This time POS is more popular compared with POW.
I don't believe that POW will still exist by 2140. Look into the past to see how much technology has evolved in 100 years. There were not even computers. Bitcoin mining will be seen as we see steam locomotives nowadays...
This crazy race for more powerful machines is unsustainable financially and ecologically. Mining is profitable where the state subsidizes energy, should I remind you too?