Best hardware for best image quality?

I just got an LG C6 OLED TV which can stream movies from my server like my old ION based Asus HTPC with Libreelec on does. However when played directly on my LG TV the videos look so much better than when played on my HTPC. All artifacts in dark scenes are gone, the quality is much sharper and in 3D the difference is huge. I never really thought that there could be such a difference in quality depending on hardware as it’s all 0s and 1s but apparently there is a huge difference.
I have plans on retiring my old HTPC and was looking at a WeTek Hub (as the Core has been sold out for months), but now I don’t know. What are people’s experiences with quality and hardware?