Priya

Worth knowing why this is uneven, because it stops it feeling arbitrary.

The actions in question have to be declared by the app in code and built against a reasonably recent SDK. Apps that were last updated years ago have nothing to declare, and there is no automatic fallback that invents actions for them. So the pattern you will find on any real phone is: recently maintained apps and system apps have plenty, a long tail of abandoned apps has none, and the middle is a mess that reflects each developer's priorities rather than anything about your device.

The practical rule: if an app has not shipped an update in two years, it is not a casualty of anything. It never had them.

Agreeing, with one correction to the timing advice people keep repeating.

"Wait 20-30 minutes for the index to rebuild" is folklore borrowed from full-text search behaviour, where it is roughly true. The action registry is not that. It is not on a timer at all, so waiting days does nothing by itself, which matches exactly what you found. That is why the half-hour advice worked for the person who told you and not for you: they probably opened things in the meantime.

If you want to speed it up without opening apps one by one, background refresh and a night on the charger will get some of them, because apps that wake up in the background can register too. It is not reliable enough to promise, but it costs nothing.

Short version: there is no supported, user-facing "rebuild the index" command on iOS, and there never has been. Everything on your list is either a side effect or superstition. Sorting it:

Does something real. Restarting, because indexing work is scheduled and a restart re-queues it. A night on the charger on wifi, because the heavy passes are deliberately deferred to when the device is idle, charging and not on cellular — this is why "it fixed itself overnight" is such a common ending.

Does something narrow. Toggling Show Content in Search for one app drops and re-requests that app's own indexed items. It is per app, it does nothing for the rest of the system, and it is the closest thing to a targeted rebuild that exists.

Does nothing for indexing. Turning Siri off and on. Changing the language and back — this one has a following because it is disruptive enough to feel surgical, and because it does force some caches to be rebuilt, but not the one people are aiming at.

Real, and expensive. Reset All Settings and erase-and-restore. Both work, in the sense that a house with no wiring problem is a house that burned down.

Planning around it is the right instinct.