OKLCH in CSS: why we moved from RGB and HSL

I'm currently battling through the CSS Color Module spec[1] so I can add oklab() and oklch() defined colors to my 2d canvas library. My hope is that it will give me (and anyone else brave enough to use my library) better color ranges, gradients and (fingers crossed) filters - such as more accurate color reduction.

The question in my mind is: now we have oklab/oklch, do I still need to care about CSS hsl/hsla/hwb/lab/lch colors? I'm tempted to dump them (except their convert to rgb code) to knock a few bytes from the library's size...

[1] - https://www.w3.org/TR/css-color-4/#lab-colors