As you can see from this thread the standard opinion is that PCs are not good for streaming. My experience has been different. I have an ASUS gaming laptop hooked up to my DAC with a USB cable (I'm using Qobuz). I have compared several CDs to their streamed counterparts through the same DAC and found that there is no detectable difference in their sound. It turns out that most people have not tried this themselves - they just repeat the conventional wisdom that you have to have a streamer to get good sound. Never mind that this "wisdom" is perpetrated by an industry that wants to sell you streamers.
If the streamed content through a computer sounds just as good as the CD then my position is that is as good as it gets. It's unreasonable to assume that you will get better sound from streaming after the WAV file is broken into packets, sent over thousands miles of wire and dozens of routers, reassembled into a streamed file, and run through another piece of digital gear as opposed to the simplicity of spinning a CD - a mature technology that the industry has had decades to perfect..
Before you do back flips and spend tons of money on a streamer I strongly suggest that you compare streaming from your iMac to a few CDs and see if you can hear the difference. If the computer sounds inferior then by all means get a dedicated streamer. But I think there's a pretty good chance that it will sound the same as the CD and you can be comfortable that your simple solution is just fine.
BTW, I do think that whatever you use for streaming, you should hook it up to the router with an ethernet cable instead of using wifi. I have 100 gig fiber and the wifi occasionally had dropouts so now I use an ethernet cable.