A lot of the 24/96 files people are raving about are from remastered sources; then they try to compare them to the original masters in 16 bit. That is not a fair comparison.
I have yet to read or experience any human being being able to distinguish between 24/96 and a normal 16 bit Flac (or wav, PCM) in clinical trials, providing the original source material was identical in both instances.
Basically, the 24/96 is a marketing ploy to get people to re-purchase material they already have. It’s the oldest marketing gimmick on earth. Trying to convince people that it has to be better because there are more “bits” there. Again, I have yet to see any data to support their claim.
But, if you want to shell out your hard earned money on something that “makes you feel better”; go right ahead…it’s your money, not mine.
Some 24bit material out there is free: Some of the sfuff on archive.org (live music recordings). That 24bit material is typically recorded at higher 24bit/192kHz, and so the 24bit FLACs are not just remastered from lower bitrate recordings.
I’ve heard some 24bit remastered commercially released stuff that maybe sounded better than 16bit PCM/WAV versions, but that could have been due to the remastering itself.
All else being equal, 24bit/192kHz stuff has potential to sound better than 16bit/44.1kHz stuff. But also we all know that some folks cannot hear bitrate-based sound quality differences other folks can, and things like headphones/speakers/etc. also have a big influence on discerning quality differences.
Few digital audio players can handle 24bit, so I always produce FLACs at 16bit anyway. The sound of 16bit FLACs, of material with inherently high quality on hi-fi player & headphones, is astounding enough for me.