All about streaming

I'm an audiophile who's been through album, cd, and mp3 formats. I currently have a laptop hardwired via usb to my audio system and usually listen to mp3's purchased through Itunes. I recently subscribed to Spotify premium which is connected to my wifi network. I've noticed that when listening to the same material, the mp3's sound much better than the Spotify version. Would I get better sound from streaming via ethernet?
I doubt it.  Ethernet or WiFi deliver the same data.  Perhaps purchased mp3s have higher bitrate?
I don't know but the audiophile community is pushing network streamers. I would consider moving to streaming, but not if there's a drop in sound quality.
I have ability to stream either from my computer or Android based TV, but I prefer just to buy CDs. I know there are more expensive streaming plans to receive CD quality (16/44.1) stream.
    Travelled this path a couple of years ago.  When I switched from Spotify to Qobuz there was a noticeable improvement in SQ. When I upgraded my laptop, & installed Audirvana SQ went to an entirely new level. I usually listen to 24/96 or 24/192 High Rez.  Not available on Spotify and the FLAC format is preferred to the lossy files from Spotify.  
Hardwired to a quality DAC and use battery instead of Power Supply on the Laptop. Good Luck.