Uninstalling and reinstalling macOS will do nothing at all. When I say nothing, I mean nothing. All of your data is stored separately from macOS. The two do not intermingle at all.
You cannot restore from an iPhone to a Mac. The sync between macOS and iOS is one-way unless you are using iCloud or other cloud storage that works on both iOS and macOS. As noted by Kilted Tim, you just need to sign into your same Apple Account.
If you wanted to import music files, calendars, contacts, etc, which are not stored in iCloud, then there is no way to do that with any of Apple's tools. You may be able to do that with third-party software.
Regardless, uninstalling macOS will not solve your problem. Erase All Content & Settings as pointed out by leroydouglas will allow you to start over, but getting to the data stored on your iPhone will not change.