I have asked the same questions as you over the last two years. Had bought a wifi extender, and then ethernet to my streamer. It was a solution, and an improvement over wifi.
Since have switched to ethernet cable (an existing 15 year old phone cable changed to RJ45).
Bought Triode Wire Labs Freedom ethernet cables. Run from from wall to switch, and then to streamer. Also a Pink Faun LAN Isolator. And a modded switch. All were improvements. Also switches and wifi router powered by Plixir LPS.
I've found Freddy22 has one message, and will argue/derail a thread. No stating his opinion and withdrawing. Continual harassment.