Sorry you were forced to change wiring. I hope it was not too expensive. I live in Europe and some things may be a bit different here but we choose to get fiber into our house a couple of years ago. I was thinking the next step would be network cables (TP-cables) around the house to everything and maybe some wifi router for phones and other things.
I ended up using wifi everywhere, it was good enough (a mesh network) for streaming video and audio. My system is not very high end so I have not tried if the sound would get better if I start using cables from the router instead of the wifi but I guess it is not the most important thing. Try to find a solution that works for you and then see if you want to try to optimize anything. A network cable should be better but if it is worth it is up to you. The fiber should be fast enough for anything you want to do unless they have kept the speed low on purpose for some reason. Our connection to the house is 1Gb/s (or about 1000 Mb/s) but I usually get a bit lower than that.