CD"S

I'm still buying CDs and sacds (at bargain pricing) mainly because I want to own it, and I work on a computer all day. The last thing I want to do when I come home is boot up another computer. Will they eventually go away? Probably, but I won't be around to see it.
I own the Yamaha CD-S2100 mentioned earlier. It is a superb unit with exceptional build quality and sound quality. The built in DAC sounds great and allows for USB input so it's got some future proofing built in.
That said, one of the best improvements in my system has been the addition of a Musical Paradise MP-D2 tube DAC. Check out some of the threads on audiocircle on this gem of a unit. It offers tons of flexibility and customization by allowing for tube swaps and output capacitor swaps.

I too buy used CDs.  I can buy them now for 1-3 bucks as people trade them in for pennies for the same titled LP.  I can buy 10 or so titles for 20 bucks, or 1 decent LP.  I burn and stream via Roon to ultra rendu andResolution Audio Cantata DAC/ CD player.  I agree now of decoupling the transport and DAC.

Don’t get me wrong. I buy my favorite titles on LP for the foldout and art; but I am very picky. I save playing the LP when I am in the mood to spin a record, but often I just want continuous like music that Roon seamlessly delivers based on my tens of thousands of tracks.

I still buy mostly CD's, but all of them have been ripped to a hard drive and are played only on a server.  The CD's I keep on a shelf for reference to their booklet, cover art, etc.  I like the access to my collection afforded by having them on a server.  

All of my CD's have been ripped to WAV files because that remains the highest quality way to store and retrieve files.  

I have a lot of CD's and still buy them (used ones).  I have a Marantz KI-Pearl SACD player and when I want to have the absolute best experience from a sound quality standpoint, that's the best source in my system.  I do have most of my CD's ripped to a hard drive for convenience and for backup.  I play vinyl a lot more often, but the Marantz is really sweet.  It sounds a lot better than anything I own for streaming ripped CD's from my hard drive.  Which isn't to say that there isn't something better, but I'm very happy with it.

"I know this question is a little hard to answer."

No, it's very easy.  There's nothing about a silver disk that adds to the SQ of the files on it,  In fact, playing the disk detracts from SQ.  Rip the CDs and the SACDs.  There are programs that do all the meta-data for you.  Once set up it's very easy and it can be set up to control completely from your phone or pad.  You can also borrow from libraries and friends to help create a collection.