As the number of desktop users are decreasing day by day because of the rise of powerful laptops, do you think the same thing can happen with laptops in the near future?
Desktops are not really decreasing due to better laptops.
Desktop sales are decreasing due to a much shallower performance curve increase.
A desktop from 5 years ago is still very valid.
Laptops, OTOH, do not have that same lifespan. Batteries die, etc.
Also, for equal performance, laptops are more expensive.