a) Room resolution bottleneck (untreated room for waf compliance, or 2 panels up for decorative purposes)
b) Old dudes, degraded hearing, untrained listeners, etc
If a, b or both are true, power products would only serve for safeguarding equipment, a cheap dac should suffice, 30 dollar cables are good to go, etc.
If this is true -- and I’d like to know HOW the average consumer can measure what matters at the outlet into which they want to plug in their gear -- then why do many people hear no difference with power products?