If this ends up working anything like the Gmail Dark Mode implementations on iOS and Android that have drove developers insane and users mad, then I expect both parties to become upset. It is easy to view this as a win for users, but the moment this doesn't work well in various scenarios, the vocal minority will punish the developers of the web as if they did something wrong here, and everyone loses.

Here is to hoping that is not the case, and they did a good job with the implementation in Safari, but I have my suspicions.