Essentially streamers are networking computers. They are optimized for sound better than bog standard computers -the previous posts touches on several reasons why a computer, which is a jack of many trades, isn’t the best at sound reproduction. Streamers also usually look like audio components.
There are programs designed to make PCs sound better. Generally they shut down the rest of the computer that isn’t playing music, in order to decrease the electrical noise generated by these functions. The programs also supply a graphical user interface, help organize your music which may reside on different hard drives or streaming services.
When I first started streaming I used a PC with the programs Audirvana. Audirvana sounded notably better than the PC running without an optimizing program.
Eventually I tired of having a computer tethered to my system. Being able to control everything with a mobile device was preferred. And while Audirvana really helped sonically, a dedicated audio device, even in the lower priced streamer end, sounded better.
Since the OP likes the CA DAC Magic I think he probably would really like the current lineup of CA streamer-DACs, which now use the ESS Sabre Chips. I own 2 CXN 60s which essentially use his current DAC. I use external DACs for both but the native DACs are no slouches. The CAs have been reliable and the app that controls them is quite good.
If he wants to go cheaper I would recommend one of the Wiim devices to use with the DAC Magic. I had bad luck with Bluesound products reliability, and for the same price range as Bluesound I would go with CA

