AB coordinates are a bit unintuitive, it's easier to visualize hues around a circle and have separate values for luminance and chroma, that's why people who work with color usually prefer LCH/HCL (Luminance, Chroma, Hue).
Chroma values in LCH differ between Hues, because each Hue has a different potential and max value. That's where HSLuv comes in, where chroma is a percentage value and therefore relative to the Hue, instead of an absolute one. This gives HCL similar usage ergonmics like HSL, thus the name HSLuv.
Sure, but chroma is absolute in LCh, which makes it hard to use for color generation. 100% chroma in HSLuv is the highest value of a particular hue in LCh.
Chroma values in LCH differ between Hues, because each Hue has a different potential and max value. That's where HSLuv comes in, where chroma is a percentage value and therefore relative to the Hue, instead of an absolute one. This gives HCL similar usage ergonmics like HSL, thus the name HSLuv.