PokerTracker

Can someone explain to me why I seem to be needing to grant access to PT4 to basically run my entire computer just to be able to use it?

Later versions of macOS have additional security requirements and without permission PokerTracker 4 will not be able to access the folders where your poker sites are saving hand histories or place a HUD on the tables. While these permissions are required PokerTracker 4 doesn't do anymore than is needed to import hands and display a HUD.