That is mostly true of ephemeral pop music. It isn't true at all for classical, jazz, classic country or classic pre-1980s reissues. All of those genres have experienced huge improvements in the past ten years. Sony in particular has worked wonders on back catalog RCA, Columbia, and Epic titles. Likewise, many 70s rock bands are going through their albums and remixing for multichannel. Just about anything remixed by Steven Wilson sounds better than any previous release. Digital restoration techniques have made a big impact particularly on pre-hifi stuff, and they are working from the original metal parts, not dubs. 78rpm recordings generally are mastered much better than they ever were in the LP or early CD era. There's some wonderful work being done, but it's on classic legacy recordings intended for adults with good systems, not throwaway pop stuff for kids with portable earphones. I'd say less than 20% of what I buy is not an improvement over previous releases of the same material. I just got a expanded version of Prince's 1999 that I'm looking forward to. His stuff is crying out for first class reissues.