Why some 4K streams still look soft on a good TV?
A 4K label does not always mean the picture will look equally clean.
Streaming quality depends on more than resolution. Compression, bitrate, source quality, older uploads, and app-side processing can all make a "4K" stream look softer than expected, especially in darker scenes, fast motion, or wide shots with a lot of texture.
That is where high-end picture processing becomes part of the real viewing experience. A TV has to read what the source is actually giving it, reduce noise without making faces look waxy, sharpen detail without adding harsh edges, and keep motion from turning into a smear.
For a model like the Hisense UR9SG, the RGB MiniLED discussion should not stop at brightness or color volume. The Hi-View AI Engine RGB also matters because it sits between imperfect everyday sources and the final image. It cannot turn a bad stream into a perfect disc-quality picture, but it can help explain why processing is part of premium picture quality, not a separate "smart TV" feature.
For anyone comparing premium TVs for streaming, the better question is not only whether the panel is bright or sharp. It is how well the TV handles the imperfect content people actually watch every day.