PSU designs are much better today.
Most high-end PSU are 80+ Certified and do require 20% load test.
Power supplies do fail, and switchmode supplies have the habit of failing traumatically. But in my experience, this is true of any power supply, from the cheapest to the most expensive. Even the "name brand" may mean little, since companies shop around for price, just like consumers. And even the best equipment can end up with bummed out components, like the shoddy capacitors that were a plague a few years ago, or by poor assembly, with transistors not mounted correctly on heatsinks, or poor solder joints, etc.
My point is, watts and cost do not mean anything, if the recommendation is to by some huge PSU at large cost - while really not drawing enough from it to be worthwhile. And names - sometimes computer PSUs will have dramatically different costs and different name brands, and the case will even look different, but they end up with the same board from the same OEM manufacturer. Add to that the uncertainty if whether you are buying the real deal, or some second cast off packaged in fake materials...