I like to say the earth is an ovate spheroid, but otherwise I'm totally with you.
To the OP: In the consumer audio world, there tends to be an overemphasis on equipment to fix problems. "Get this to fix that" is driven in part by the marketing machine of consumer electronics but also simply by the desire of the consumer to buy a product and be done with it.
Rooms are in many ways the hardest part of the equation because they're usually firm and fixed long before a sound system is installed. We buy or rent a place, and we use the rooms that are there, unless we've got the cash or skills and time to change the physical layout. So, we turn to treatments to make the room more of a sound-friendly environment.
One of the best things I ever did was spend thousands of dollars on expensive equipment and put it in the wrong, untreated room. Disaster! Disappointment! Despair!
But, lesson learned.
Hundreds of dollars and lots of DIY work later, the room was transformed and the system then was able to become a thing of wonder.
I went on to do minimal room treatments in other rooms in the house which had audio systems in them, and each one improved dramatically, especially as I gained experience and studied the science of it. The reading and learning was free, and the solutions were simple and less costly than I imagined (as largely DIY projects).
When I finally had the $$ to convert an existing room into a dedicated HT, the acoustical properties of the room and the fundamental treatments needed were the first thing we did, long before a single speaker or electronic device was installed. When the speakers and other gear I had chosen were put in place, there were some minor tweaks to the location of a couple of absorbers and diffusers, but everything was almost perfect already.
People who get excited about this subject of room treatments usually suffered through years of equipment purchasing and replacement in pursuit of sound that was not possible in the rooms we had--until we took care of the rooms themselves.