Sites that use the prefers-color-scheme media query honor the OS setting on iOS, but it obviously doesn't work on sites that haven't implemented it - Dark reader[0] takes a invert-colors approach and makes it a little easier on the eyes.

[0] https://addons.mozilla.org/en-US/firefox/addon/darkreader/

well adguard only have ip, domain names etc. I mean it has less context? Addon has more context about the webpage lets say it can remove ads belonging to DOM with id #ads-1 ?