The cardinal principle of optimal allocation of scarce resources is that the yield from different uses of the same scarce resources must be equal at the margin.
Time is a classic example of a scarce resource.
Because of sustained economic growth, the productivity of work time has substantially increased. To achieve optimal allocation of time, the yield of non-work time must be increased to match work time productivity. Since some of the non-work time is devoted to leisure activities, our leisure has thus become harried in our attempt to increase its productivity. To increase the productivity of leisure time, we tend to prefer activities whose productivity can be easily increased with more goods that can now be afforded with our higher income. Just as workers become more productive by working with more tools and capital equipment, consumers get more out of their leisure time when more gadgets are used per time unit.