Noise reduction -why the rage now ?

Is it better science ? Or more needed today with the ’surge’ of switching power supplies, smart phones and Wi-Fi routers ? Then, higher-frequencies in digital interfaces -now megahertz and gigahertz.

The problem with the "needed more today" theory is that one, listeners are hearing things they never heard before. One report is from Paul of PS Audio (on his blog) stating that a 4K power cord transformed his system. Yet he sells a Power Plant.

Two, many reports of lower noise (in the last 10 years) were in systems with linear power supplies, not switch-mode.

Three, for digital, many people were using AES/EBU or i-squared interfaces. These don’t have the noise concerns of USB.

Fourth, many people listen at night. They know better, due to the problems of a noisy day-grid.

Yet, there it is -large gains from the latest power conditioners, ground blocks and after-market power cords. To me, today’s science is much better at doing this. Along with the "need today".