Any audiophile use computer (MacBook) as your audio streaming source?

Re lossless etc., it will depend a lot on your software config, i.e. through web browser (poor), dedicated app (depends), or something like Audirvana/Roon (can be excellent). 

Re computer vs. streamer, once you get an external DAC, the streamer (with built-in DAC) argument evaporates. Needless to say, there are different levels of external DACs, so your choice.

IMHO, streamers are utterly overpriced for what they are, and you have to take the DAC that the manufacturer slaps in there. The whole "optimized OS for audio" is marketing hype, considering the minuscule computational power it takes to play/decode/transform audio signals compared to processor power in current computers. I assume you do not intend to run it on an ancient MacBook 140 from 1985. You can look at the activity monitor when playing music, and it is insignificantly different from when nothing is playing. I also assume this would be a dedicated computer for audio, you're not also 3D rendering while trying to stream music.

I use a Mac mini as a Roon server, and that gets distributed.

1) USB to Holoaudio May DAC L2 [I challenge any streamer on audio quality] in listening room.

2) LAN to computer with older Topping D50 DAC (computer workstation with bookshelf speakers & headphone rig)

3) LAN to Laptop with dongle DAC and earbuds for couch surfing.

4) LAN to Living room in-wall speakers through a Rotel RA 1572 integrated with built-in DAC.

Audio quality is fine in all cases, considering limitations of various set ups: in-wall speakers do not produce a soundstage like my listening room, but perfectly enjoyable when I cook. etc. etc.

I used a computer for at least 20 years before  moving on (up.) No comparison. One can believe computer sound to be *good" if you never hear the difference.

I used a Mac air for years and to my ears it sounded fantastic. I did tried dedicated streamers from the the Eversolo 6, master and 8. I even tried a Hi Rose 130. Not even it was appreciably better. The Aurender N200 got slightly better. It took 12k and a Aurender n20 to get noticeable better. That what I have now feeding my Holo may Kte. 

Re computer vs. streamer, once you get an external DAC, the streamer (with built-in DAC) argument evaporates...IMHO, streamers are utterly overpriced for what they are, and you have to take the DAC that the manufacturer slaps in there. The whole "optimized OS for audio" is marketing hype, considering the minuscule computational power it takes to play/decode/transform audio signals compared to processor power in current computers.

This is absolute garbage advice by someone who clearly has no idea what they’re talking about. Listen to the others here (including me) who’ve transitioned from computers to a dedicated streamer and found a night and day difference. You’ve got your answer.

Streaming music through a computer is yesterday's technology. It is way too noisy. If you get a separate streamer with an adequate ethernet line cleaning method you will know what we are talking about.