Besides firefox, more than 80 userland programs have their access to the filesystem restricted with the use of unveil.
2024-01-08 22:34 ubuntu@knope:~$ sudo apparmor_status
apparmor module is loaded.
185 profiles are loaded.
104 profiles are in enforce mode.
(...)
124 processes have profiles defined.
122 processes are in enforce mode.
including firefox and chromium