Ethernet

Honestly modern Wifi is really good, the biggest issues I know of are related to contention on the same Wifi channels and RFI noise. 

I always suggest users get a free phone or laptop Wifi analyzer to help them see their Wifi neighborhood.  Pick an unused channel and park your router there. 

@maprik ​@soix 

For what it’s worth, I am not an expert, but, I agree with soix.  Unfortunately, you have to be willing to spend more money.  There are 5 things you can do, I believe each will give you benefit.

1.  eero mesh nodes
2.  5 volt Linear power supply to the eero mesh node connected to your streamer
3.  Audiophile quality ethernet cable from your eero mesh node to your streamer
4.  Ethernet filter between the eero mesh node and your streamer.  I use the stack audio smoothlan filter
5.  If the internet coming into your house is not fiber optic, but, older Copper cables (ie. DSL), then, you can do a copper to optical conversion from your router to your first eero mesh node to get rid of the noise coming into your house on the copper lines

Here are a couple of pics. 

copper to optical conversion and back again.

eero mesh to hard wire ethernet to stack smoothlan filter with LPS power supply

Fully agree with the concept but premium ethernet cable of that length like DH Labs Reunion Cat 8might be pricy (close to $500).  You might want to consider much affordable fiber ethernet combo that might render equally good result.

@maprik  @lanx0003 

lanx0003 makes a great point which I missed in my response !   You could take the copper to ethernet conversion in my picture and use a 25 foot fiber optic cable and put the other 10Gtek or similar to convert back to copper ethernet near your stereo and buy a nice shorter ethernet cable to connect to your streamer...  Fiber optic cables are cheap and get rid of all the noise...   You might want to get the 10Gtek or similar with the separate switching power supply and buy a 5 volt linear power supply instead to run it.  This will help to ensure that the 10Gtek is not adding noise to the line on conversion.  An ethernet filter between the streamer and the 10Gtek could also help,.  This will be much more cost effective than what I posted earlier and you will probably achieve similar or maybe better results.  Note:  If it was possible to hardwire my streamer from my router instead of buying eero mesh nodes, I would have also done that with fiber optic.

I don't have an actual hard wired router in the location where my setup is but would a streamer benefit from being connected to a wireless access point via an ethernet cable that is connected to a mesh setup over connecting directly to the streamer's wifi? I'm wondering this for an Apple TV as well.