Personally I'm just here to find more deep cuts and don't have hard cutoff years for my interest/enjoyment. I admittedly have a lean towards late 90s/early 2000s library music, but I've also found gems from the 2010s as well, and do want to dig more into vintage library music when I get the chance. I understand why there's low interest for 2nd half of 2000s onwards, or even 90s onwards, although I'm sure there's lots of great tunes from the digital age. I suppose it's that pre-90s library music has more of a distinctive feel to it?
To me, the "good sounding" music stopped at the new Millenium. I don't mean only compositions and styles, but also the way they are mastered. Loudness Wars is just a big part of it, but also music shifted vastly away from what I enjoy. For example the "Exotic years" when 5 years long, many people tried to copy KYGO with sparse carribean soundscapes and high-reverb (and thus spacious) percussion. Or the wobble bass years (Dubsteb). For example, if you look at 2000s "rock" music, it will be like Nickleback clones or "Retro 80s" albums. Why not going actual retro? The same with all these new "Synthwave" producers mimicking what I have pently of directly from e.g. CAVENDISH MUSIC's "To Every Action..." from 1988.
If I look for "Technlogy" in the music libraries and I see a CD/LP cover with a close-up of a Z80 and I hear slap bass, synthpads and in general a well-made mix that you can actively listen to compared to a 2015's produced "Technology" album that is hot-mastered and its wave form preview looks like a sausage - two ends and a big block in the middle - full of gritty, almost-industrial sounds, I know I don't need to look further. Again, the worst thing is to argue about taste in general, might it be music, sports teams or favourite ice cream flavour. But man, if I could make a chart of the release years of "my music" it'd drop massively from 1995 onwards even though my latest track is from 2005 - because it sounds genuinely good and interesting.