How to backup all brushes, preferences, settings, before updated OS?

https://prepression.blogspot.com/2017/01/photoshop-custom-action-file-backup.html

https://github.com/MarshySwamp/Backup-Photoshop-Settings-Universal

Mac OS Example:

• /Users/username/Library/Application Support/Adobe/Adobe Photoshop 2021
• /Users/username/Library/Preferences/Adobe Photoshop 2021 Settings
• /Applications/Adobe Photoshop 2021/Presets

Win OS Example:

• C:\Users\username\appData\Roaming\Adobe\Adobe Photoshop 2021\Presets
• C:\Users\username\appData\Roaming\Adobe\Adobe Photoshop 2021\Adobe Photoshop 2021 Settings
• C:\Program Files\Adobe\Adobe Photoshop 2021\Presets

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

I am using Windows, and have taken to keeping presets in a My Documents folder, and placing a shortcut to that folder in the original location.  I also do that with some of the .8BF plug-in files (usually the old ones) that don't seem to survive a major update.  I do this so when I add a new preset group, it is available in both full release and beta versions, and because it makes sure I don't lose anything with a major update.  I'd like to do the same with custom workspaces, and actions, but I change them a lot so have to share them manually.

I see you’re on a Mac. I use the Time Machine backup feature that comes with macOS, which means I don’t necessarily have to manually back up any specific files, because they’ll be included in the backups that Time Machine makes automatically every hour.  For example, if I upgrade an app today and things get weird, I will go into Time Machine, set it for any recent day before I upgraded, and restore the settings files from that day.

That can also work if you are using any of the other Mac backup apps that support incremental backups, especially those that support the macOS APFS Snapshot feature which is how Time Machine makes its backup snapshots.

Now, regarding what files you are looking for…refer to the Adobe help article in the link below. In the article, look up the settings you want to back up or retrieve from a backup, and it tells you the path to that file. Also note that almost all of the settings files are stored within the user-level Library folder that macOS hides by default so to quickly reveal it, switch to the Finder, and hold down the Option key as you click the Go menu. As long as you hold down the Option key, you’ll see the Library command added to the Go menu; choose it.

Preference file functions, names, locations | Photoshop