"tonality characteristics" and "soundstage" are subjective words that have no concrete definition. Other similar words are "grain", "speed", "separation", "resolution". They can't be objectively measured, and are most likely just another function of frequency response.
The differences between headphones are most likely your ear having a different shape from the reference ear used to make the eq targets, leading to a different final perceived frequency response. (or limitations in the accuracy of the measurements, most targets I believe are "smoothed")
I'm going to trust the (claimed, who knows, maybe oratory1990 is a liar) consensus of audio engineers over your anecdotes. As I said there are plenty of audiophiles whose "lived experience" is that $2000 golden cables are necessary and that they can tell the difference between any $200 and $1000 DAC (even though a decent DAC in that price range already has a dynamic range and signal-to-noise ratio of 100-120dB which should be totally indistinguishable from perfectly clear audio for all humans
personally the only decent-ish headphones I have are DT 880 600 ohm and a JBL 760NC. The latter kind of fills all the boxes of being a wireless headphone and has poor reviews and a poor default sound profile. But after EQing both, I can't really notice any difference except when very carefully doing side-to-side comparisons (besides the much better comfort of around-ears vs over-ear).
In contrast I believe I can tell, with some songs, the difference between 320kbps mp3 and flac (just 44.1khz), but even there I'm not sure it's not just placebo
Usability is kind of secondary, android should have jamesDSP and the venn diagram of people that know the best headphones to buy (instead of beats by dre) and who can setup an EQ (install an app and follow written instructions) should have a lot of overlap
I will say though that more expensive headphones are probably going to last longer and are probably much more comfortable
realistically, the linux foundation gets all its funding from corporations who have interests in servers, android and embedded. So all the funding goes to those things and not to the linux desktop.