the Apple universe is not the bar to better sound. nor is it a problem for streaming.
an apple TV is not the answer at all. unless it is a second gen ver. after the second gen, all ATV use only HDMI outputs. no other interface for audio out. the second gen had an optical out and HDMI. now only HDMI.
the trick is to get the files converted into analog so the amps du jour can make pretty noises.
if no possibility of ethernet connectivity is available, the converter has to rely upon WY FY.
I’m not up on all the streamer options out there and there are DACs which allow connection via wy fy… and or LAN… I think.
for full wireless connectivity folks here tend to mention Blue sound Node 2 as a starting point for $500 retail. I’ve not found another less expensive option yet, and there are those whose fidelity are significantly better, but at higher prices.
another moderately priced path could be to use a later model Oppo as 100 or 200 series, a DLNA or UPNP player, if whatever app can see it, ala J River, ROON, Fubar 2K for MAC, etc. Oppo also says there are free third party server apps which work on MAC platforms. and their disc spinners.
those are the two least pricey choices as I understand it. I’m sure there are others for more $$$$.
the likely prefered path is getting a D/A in the mix to feed your amps. even with the BSN II feeding its signal to a DAC would be at the very least a step I’d have to employ even if it were for an office rig.
maybe Shitte has a solution that will work for you.
good luck.