When all websites respect their settings and they don't like what the websites do, they will search "how do I change X...", which would point them to the brows

When all websites respect their settings and they don't like what the websites do, they will search "how do I change X...", which would point them to the browser settings. If no website respect them, they won't bother. Also these settings come from the OS, which asked the user on install what e.g. date format he wants to use.