Many so-called "4K" releases are actually upscaled 1080p files that look worse than native FHD due to artificial sharpening. The tag guarantees native 1920x1080 resolution with a consistent bitrate. Users report that these files are optimized for:
It represents a rebellion against algorithm-driven content curation. It is a return to the "scene" ethos of the early 2000s, where release groups took pride in their encodes. If you value bitrate over convenience and untouched audio over fast loading times, hunting down an fhdmoviesxyz exclusive is the only way to watch.
If you are searching for the tag, you likely already know the domain. However, for newcomers: