I have never had a need to install acoustical treatments as I am not in the habit of installing audio equipment in public lavatories.
I have used speakers in a wide variety of locations while making live recordings and have never encountered a room I could not reliably monitor in.
In our home the AV room has designed optimal dimensions and there are architectural features to optimize the room, but no ugly sound treatments.
The great room and family room have no special treatments and sound excellent.
So no, I have zero need of acoustic treatments. Family and friends voices sound normal and as they always do. So speakers should NOT require special treatment, and if there was a problem the speakers would be studied and likely redesigned in some way.
The OP's question could have been answered with "Yes" or "No".
Speakers don't require treatment, ROOMS require this but some speaker choices make it necessary. Speakers should be chosen for their dispersion when possible, but if you check consumer speaker systems, polar dispersion patterns aren't usually offered, while commercial/industrial product technical information DOES include this.
This thread isn't about your room & preferences, your rooms have nothing to do with anything outside of them and you don't seem to understand the scope of the acoustics industry or why it's necessary. Do you think architectural schools teach acoustics for their health? No, they teach it so fledgling archis don't go into the world, designing acoustical nightmares.
Room treatments (literal or coincidental) are in every private and public place, visible, or not, and in many places where reflections and echo are a problem. Acoustical problems exist in almost every building and when the space has minimal objects and furnishings, the problems remain while furniture that's made of hard/non-porous materials do little to help. Adding some soft materials and objects makes a big difference. Changing the place isn't an option for most people.
In contrast to your anecdotal opinion, my house is older, isn't going to be changed by me beyond what I have already done, and when I have used any speakers, had problems in the upper bass below 100Hz. I tested the panels I made for a demo in a home theater build while I ran REW and could easily see that with each panel came improvement in the response. Ultimately, I was able to eliminate the problems and the sound is much better. Is this because I'm delusional? No, it's verifiable objectively AND subjectively.
EVERY room has its own sonic signature and some have sonic problems because of the materials and/or dimensions but thinking that your system is perfect is, as you would say, bollocks. Not the dog's bollocks, just bollocks. You prefer it above all others and that's ideal. It may well be the best room in history but statistically unlikely but I would also ask- is your hearing perfect? It's possible that you can't hear something that could be measured and found to be 'out of the range for perfection'- we all lose hearing acuity.
You're fixated on the idea that the speakers are at fault in all cases, when the rooms can be and are the problem. Those problems CAN and ARE addressed in professionally designed spaces, research has been done for many decades and if you do some research, you would find that reverberation over a specific time range makes music virtually un-listenable and speech unintelligible.
You want to think in absolute terms but that's not practical and it's not applicable in applications outside of your control.
Acoustical treatments can definitely be ugly, but many are unnoticeable and many look like wallpaper or painted surfaces- not all are panels that hang on walls or from ceilings.
