I absolutely agree

I would read KaiS comments on the Harman Curves, e.g. this one and others.
Simply use extended forum search and search for "Harman" and user KaiS, then you will find a couple of threads.

https://forum.rme-audio.de/viewtopic.ph … 06#p222606

My approach is currently the following...

I gave up on all these curves and also Sonarworks for active monitors.

Especially, headphones can sound very different depending on
- how somebody analyzed the sound (placement of the mics)
- how the headphones sit on your head
- which ear pads you use, whether the leather is rough or whether the ear pads are softer, which lead to another placement on the head
- and then, of course, the usual deviations between different headphones

Here’s my case with the LCD-3: The Alcántara ear pads are no longer available, making my headphones incomparable to Harman measurements. The sound varies depending on the pad material—rough Alcántara, which creased more and changed the fit, or smooth leather with firmer padding. There were also different model variations with varying Fazor technology, which led Audeze headphones to produce different sounds.
As Bob Katz pointed out years ago on Innerfidelity. The LCD-X which he had initially for demo and which woke his interest for this headphone sounded different from the one delivered later. Different characteristic in sound/bass, I can't remember the details.

You can't change the world, you need to accept such deviations. For some products more, for some less.

Therefore, I am coming back to the approach of simply using my gear and to getting used to it how other professional recordings sound. Additionally, I always focused on getting headphones and speakers which deliver a reasonable / "natural" sound.
I know how most instruments sound in real life, also thanks to my musical education at school (long, long ago).

I am now using only a few corrections for Bass and Treble as my LCD-3 does not fully deliver the Bass of an LCD-X. Same for the closed headphones DCA AEON 2 CB, which has even lower Bass.

But that's all. I fear that too many false corrections at the end make it even worse than before.

Then I am simply getting used over the months and years how professional recording will sound over my gear.
Not only headphones, also when using active monitors.

This is BTW one of the biggest criticisms of studio owners towards solutions like Sonarworks if you cross-check information from YouTube. It will alter the sound, and all the experience that you have, how your gear sounds or how your mixes should sound will go away, and you will have to start new as if you had new gear. So, a loss of a broad range of your experience.

Only my opinion to that, but I would encourage you to not see the "holy grail" of truth in such measuring / Harman Curves.

Imho that is very shortsighted criticism. Calibration is there for a reason, which is to comply to a certain standard.
Surely it needs some time and careful listening in the beginning. In the long run it will make work much easier and mixes translate better. Especially when moving studios, working elsewhere, buying new monitors etc.
With immersive setups employing height speakers it’s even more crucial, it’s rare that all reflection points can be properly treated for every loudspeaker.

Or do you mean that room correction isn’t applied to browser playback from YouTube? In fact it is with sonarworks systemwide, (at least for stereo and there are many software solutions for surround, too)