Decent ambient music at the system level. To me, at least, this simple feature, which any and every computer or mobile device company could have done decades ago, is more deserving of promotion than, say, all of "Apple Intelligence" (now in some kind of growing-pains-esque stage of seeming woefully and misguidedly over-hyped to this point).

And it's strangely hidden. As far as I know, the only way to access it is by adding a button to Control Center using its new, dedicated, and somewhat awkward interface for adding and arranging controls. There's no built-in app for it, no widgets around it, no Shortcuts actions to activate it. I suppose it's internally considered a sibling of the existing "Background Sounds" feature.

And, deceptively, it's almost as expansive as it is hidden. You can add any of four buttons ("Sleep", "Chill", "Productivity", and "Wellbeing"). "Sleep" is the one you want, I'd say to almost anyone.  The others are perhaps technically "ambient," but laden with beats and other complexities – at least, if it wasn't possible to enter Control Center's edit mode, tap the previously-added button, and select which playlist you'd like to play from, following which it turns out that each button style includes at least one reasonably dulcet and unpercussive selection. That's a lot of options, and to this point I haven't even found an official support article about them.

I certainly hope this is some kind of seed that expands to higher prominence in the future (as well as to the Mac), and that other companies feel free to mimic this. Computers have been wondrous worlds for half a century now, and something like inspired ambient music feels like it's been a missing sensory component of such worlds.