iOS (iPhone) "Other" storage category is huge

Solution 1:

As Steve Chambers commented - this was the ONLY thing that worked:

• Backup phone on itunes to your local computer (not iCloud).
• Wipe/Reset phone completely. Delete all data and settings.
• When it comes back up, plug into your computer again (or just leave it plugged into your commputer the entire time).
• In iTunes, click restore from backup (the one you just made locally on your computer).

It will reload all your apps and settings to nearly the exact same (I had some things that randomly didn't restore properly and had to handle myself). You'll also have to login again to some apps, but others you won't.

It also takes a long time, and is generally a pain. But, given that this problem is all over the internet including on apple forums with no response or help from the company (typical), I will depend on this in the future too!

Solution 2:

Settings → iPhone Storage

Delete any apps you never use. Then at the bottom, "On My iPhone," look at the local files for app you do use and delete files you don't need.

Alternatively, in Finder on MacOS, plug in and select the iPhone. Go to the apps tab and look through the files different apps have stored. You can delete them, or move them to the Mac.