We're sorry about the trouble while trying to launch Photoshop. Would you mind telling us which version of Photoshop are you using? Please ensure you have the latest version of Photoshop (22.4.2) installed on the computer. At what point, while launching does Photoshop freeze?
Since you're on macOS Big Sur, please ensure that Photoshop has the necessary permissions on the Mac by following the steps suggested below:
1. Go to the System Preferences for your Mac, then Security and Privacy, then select the Privacy tab.
2. Then select Accessibility from the list to the left & check if Photoshop is added to the list with a check mark in front of it.
3. If Photoshop is not a part of the list, please add it by unlocking the window first using the lock at the bottom left, then clicking the + icon & navigating to the Applications folder.
4. Also, grant permissions to Photoshop under Full disk access located in the same list as Accessibility.
5. Once done, restart the Mac & check if it helps.
If the issue persists, you can try to reset the preferences of Photoshop manually using the steps mentioned here: https://adobe.ly/2Qzc0K3