why have my bookmarks on safari disappeared from my Mac and phone

Hello gigii12,

Thanks for using Apple Support Communities. We understand that your bookmarks are missing. If you were syncing bookmarks with iCloud the bookmarks can be restored from an earlier version using the steps in the following resource: If you accidentally deleted your calendars, bookmarks, or contacts from iCloud - Apple Support

Let us know the results. Be sure to include any other steps that you may have tried.

Have a nice day!

gigii12

Thanks for getting back to us.

You can check to see if an extension is to blame by booting into safe mode. Here's how: How to use safe mode on your Mac

"Safe mode prevents your Mac from loading certain software as it starts up, including login items, system extensions not required by macOS, and fonts not installed by macOS. It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed."

Let us know what happens.

Have a fantastic day!