I have found that it is not so much the medium as it is the particular mastering. A lot of streaming sources do sound bad, but then, so do a lot of currently available CDs of the same music. In many cases, older CDs sound WAY better then current reissues. It comes down to how the digital mastering was done. That is one of the reasons why certain CD reissues command exorbitant prices on Discogs, such as Japanese reissues.
I think it is worthwhile having a CD player and buying used CDs; they can be quite economical to collect. But, I don't think one loses any quality by ripping the CD to put on a streamer/server. The sound quality of a server can be as good as that of a CD player and a server makes your collection much more accessible and convenient. Also, streaming services can give you access to way more music than you can possible own, even though quality is sometimes not ideal.
