What game was it? On my limited experience as a newer audiophile, both my Sennheiser hd 600's and my Dekoni Blues sound amazing on modern games with great sound design. Things like Halo Infinite, Battlefield 2042, age of empires 4, Doom eternal, etc, sound really really good on my headphones and when I do a direct comparison to my old gaming headsets, they should like you described, tinny, underwater, empty cans etc.

Did your friend have any audio processing on? Like a DTS or Dolby for headphones? All that 3d audio nonsense makes any pair of headphones kinda sound like shit.