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.

For all those who used computers and say that streamers are better, what DAC did you use in conjunction with computer? Could it be that the DAC in the streamer is better than what you used when using a computer as file source? So what you are hearing is not computer vs streamer, but different DACs.

Also was the computer spinning disc or solid state?

I stand by my "total garbage" indications above. Great ad hominem, BTW. LOL!

Re jitter, the article below suggests that jitter is a red herring in the vast majority of contemporary DACs.

https://audioxpress.com/article/audio-electronics-is-digital-jitter-really-a-problem#:~:text=For%20a%20given%20amount%20of,%2C%20but%201.0%25%20at%2010kHz.

Even if you don't like Winer, the question of audibility deserves consideration. Happy to hear other well-informed, data-driven opinion on that matter.