Touché, this is the point that enrages the people that already blew their discretionary income and engages those who have cash reserves.
Did you ever wonder why you almost NEVER see reviews of room treatments and the only way "audiophiles" ever measure their acoustics is with an obscure app called REW that must be studied like learning calculus?
The fact is that room treatments are boring, you don’t plug them in, they can look disgusting on your walls if you don’t cover them with acoustically transparent fabric.
You get the room right and a $500 receiver can sound like a $$$$ amp in the average listening room that has sound waves bouncing off windows, ceilings, dry wall, etc. like its the Titanic.
This is fact, I didn’t invent acoustics. Sadly this is why many people are on an endless journey of upgrades, because it never gets quite right acoustically and no speaker, no DAC, no cable can fix a FR that looks like one of those old TV test patterns.
Here is a video on the topic:
The math on getting decay time right starts at the :40 min mark, the "recipe" of what to do follows right after the math:
https://www.youtube.com/live/G0ekssXX7rE?feature=shared