What makes you believe that?
I believe Hi-res can add something (more room to breath and dynamics) based on personal A/B comparison. I say "can" because sure, it depends on:
• The quality of the original recording
• Te type of music recorded
• How revealing the equipment is (no weak link)
• Room treatment
• The listener (Not everyone can accurately tune a music instrument, not everyone's hearing is the same, not everyone likes the same sound signature... ... ...)
I haven't compared Hi-Res with 16/44.1 on the latest DAP players therefore I will refrain from quick conclusions or skepticism towards them. But sure, I am aware that many manufacturers have been using the Hi-res gig to lure people in making them believe Higher-res = better sound when in fact no difference happened (I've seen it with a $1600 CD player...) I've also seen manufacturers advertising DAP/DAC as 48/192 when in reality, the restitution is down sampled (!)... millions of dollars are made like this with no difference in the end, sure. Same abuse goes with the industries of Home audio, Home Theatre, cables... I hear your point, I'm neither closed minded nor gullible of the audio fluff/hypes going around.
All I'm saying is all the right conditions need to be there for the improvement to be audible.
But maybe you believe that regardless of who is listening, in whatever situation, with whatever equipment/recording... Absolutely no one can audibly tell the difference between 16/44.1 and 24/96 and if one claims to, it is purely imaginary? Is that it? (I'm asking because I am not sure I fully understand your point)