Hello defaultkzeu9aowqcxi,
Sorry to hear about this experience. As suggested by Mike, I would recommend you try resetting Illustrator's preferences manually by following these steps:
• Close all Adobe applications.
• Go to the following locations
• ~/Library/Caches
• ~/Library/Application Support/Adobe
• ~/Library/Preferences
• Rename Adobe Illustrator, com.adobe.illustrator and Adobe Illustrator 26 Settings folders to Adobe Illustrator.old, com.adobe.illustrator.old and Adobe Illustrator 26 Settings.old
• Launch Illustrator from the Creative Cloud.
Note: Location starting with this "~" sign indicates the User Library, which is hidden. So, you need to copy & paste the exact path in spotlight search or from Finder Menu > Go > Go to Folder > Paste the location in the dialog box like this:

Disclaimer: Please note that renaming preferences folders will remove all the custom settings, and Illustrator will launch with default settings. You can also take a backup of the folders in case you want to. The location is mentioned above.
If the issue persists, kindly try running Illustrator under the root user account and check if it helps.
Looking forward to your response.
Thanks,
Anubhav