Is Stream via ethernet Superior to BlueTooth?

Ethernet is wired so there is lossless transmission. Bluetooth is inherently a lossy protocol so that is the difference.

You hearing that difference is another different thing @bernadie5317 

Yes, if you have a pretty quiet room, you should be able to hear the difference. The difference is reduced quite a bit if you are using one of the newer, lossless codecs like LDAC or AptX HD.

That said, if the source material is compressed (say mp3 or whatever Apple uses), you may not hear a difference from better transmission. But if you are using uncompressed digital info, say from FLAC files or Tidal or Qobuz, there will be an improvement from avoiding Bluetooth.

I used to insist on wired ethernet, now wireless, IF a good signal, can be quite good, but the distance and signal strength is just part of it.

it's not cut and dry, you need to educate yourself about Codecs ......

https://www.audio-technica.com/en-us/support/audio-solutions-question-of-the-week-what-are-the-differences-between-bluetooth-wireless-codecs

Wifi is different than BluTooth.  Wifi has essentially the same bandwidth as Ethernet.  The isseus as pointed out is whether you have a strong, uncontested signal. 

The use of a phone or laptop based Wifi analyzer to help sort that out is really useful especially in wifi congested areas. 

At home I have a mix of devices but for my serious music, work and Home Theater I only use Ethernet.

A proper network connection supports higher resolution than Bluetooth.