Settings having a search facility is helpful. Something like `apropos` that searches all installed apps and suggests matches seems like it would already be in the latest gen phones?
You still need to know that something exists and how it was named to be able to search for that setting.
You need to have an idea it exists, but with well designed search/indexing you shouldn't need to know the name of it. E.g. "duplicate screen" "copy what's on my display" "mirror to another device", etc., should all show "MirrorShare" (and possible other options) on Android.
-we have feature X but only 1% of users find it where 10 of users use it after someone else shows them how to use it. Maybe a feature that is only for 5-10% of users is advanced or niche but we need to design it better so this niche/advanced features are irrecoverable.
I do not know how to solve this on mobile, I know that some software on desktop has a tooltip dialog when you open it(with a checkbox to disable this feature) that presents some cool advanced feature, you can click Next and Next to see more and more advanced features. I seen this in Intellij, they also have a list of the actions you performed sorted by usage, so you can look at it later , notice you used action X the most and that you can speed it up if you learn or configure a shortcut