Why is ‘every day’ the lowest setting to remove them automatically and not when I close the app?

Instead you can use the “Delete browsing data on quit” feature but only enable “Open tabs”, tho this feature by design only works if you close the browser by pressing “Quit” from the 3 dots button on the toolbar

had that issue since updating my phone to android 13, mozilla really needs to fix it

use 7zip zstd!