And yet, one of audio's long-time reviewers (Srajan Ebaen with 6moons) uses an iMac as his source in his main system. Of course he has add-ons, such as an outboard SSD, Singxer SU-6 DDC, and LHY Audio switch, but still. He recently used that source when reviewing the 20,000 euro Cube Audio Lotus 10 speakers.
To the OP, I suggest you try Holo Audio's Red DDC/Streamer for $800. You can first try it as a DDC between your MacBook and DAC, and then maybe as a stand-alone streamer. If you use Roon, you could try running Roon core on your MacBook and Roon Ready player on the Red, as a streamer. Later, if you choose to add a server, you could try one of the SGC models or one from Roon, run it on your network, and use the Red as your streamer. Even if you eventually upgrade to a better streamer, or a server/streamer, the Red is one of the better measuring DDCs that offers both galvanic isolation and reclocking prior to your DAC. It also outputs I2S in the event you purchase a DAC with that type of input. The Singxer SU-6 DDC is also good but the ability to use the Red as a streamer also may make that a better deal for you. Lots of versatility and something that could make an immediate positive improvement, without changing out your MacBook, for only $800.

