[righthand]

I just tried to do this and Apple has obfuscated that there’s even a 16:10 option. You have to click deep into the Displays customization presets menu. They don’t even label the presets with a display ratio and have them labeled with some obscure Apple design lingo (Apple XDR (P3-1600 nits)).

To change it you have to first display the hidden list by enabling a “display resolutions list” toggle.

That is not something a “I love Apple because it just works” person can figure out.

[lilyball]

Those presets aren't display ratios, those presets have to do with color profiles, HDR support, etc.

[righthand]

Exactly my point. The setting you’re likely looking for is hidden and a similar one of even more advanced color profile technical options is front and center.