The difference with the "new" dark mode on Windows, MacOS and now iOS/ipadOS is that it's a system wide setting. Apps and even websites can (or rather should)

The difference with the "new" dark mode on Windows, MacOS and now iOS/ipadOS is that it's a system wide setting. Apps and even websites can (or rather should) support it. How many hours would you have spent modifying themes, creating new css rules or installing extensions in browser to get those results before? And you'd still not be able to do so with most apps/software.