OKLCH in CSS: why we moved from RGB and HSL — Evil Martians’ team blog
Persuasive article on why OKLCH is the best of the "new" colour formats coming to CSS. The arguments are essentially: it retains the "readability" of LCH (it's fairly easy to guess what the colour from the code), it supports a much wider range of colours ("wide-gamut P3"), it prevents issues when changing colours programmatically (e.g. via a darken() function) as it models human colour perception much more closely - which also helps with preventing colour contrast problems.