May I ask if your preference in terms of performers meant that they were recorded at a certain era? Nearly all modern (i.e produced after 2000) have "fine to excellent" sound, so I would agree with you there. However this was not the case for some labels in some eras. Deutsche Grammofon from the early digital age (80's) up till the late 90's had a notoriously muddy sound. Prior to that they sounded mostly decent but not outstanding. Decca from the 50's up to late 90's had variable quality, some were really good, and some not so great (good example is Solti's Wagner Ring cycle, supposedly a breakthrough in sound quality with the famous John Culshaw, but modern remasterings sound awful). The same variable quality can be heard with EMI of all eras. The only consistently good recordings (as in, I haven't heard a bad sounding disc from this label) come from Hyperion, ECM, Alia Vox, and surprisingly - modern Deutsche Grammofon.
I have a few thousand CD's because that's the only music I listen to. My focus is on collecting historical, famous, or unusual performances, which usually means digging through older recordings and sometimes on smaller labels. For example, Jascha Horenstein's recordings of Mahler are particularly rare, and you have to really hunt down small labels that I have never heard of, e.g. Unicorn-Kanchana, VoxBox Legends, and so on.
My point is, if your taste leads you to some performers (which would mean recordings were made at a certain era), you might form a biased view of classical recordings. I could on balance say that nearly all classical music from the earliest recordings in the 1920's to early-mid digital era are inferior to modern recordings, which would mean that the majority of recordings were substandard.
I would also like to know how you determine a recording to be "objectively fine to excellent". The only way I know of is to listen to it.
