Hello,
I use brave both on a desktop and an iOS.
For desktop (Windows 10) I have my cookie policy set on strict, I know it breaks some websites but I like browsing randomly with this feature on. Whenever it does break a website I really want to see, I can always alter the local shield and allow some other cookie policy, which puts this privacy feature into my hands.
For iOS version, though many features can be altered for a specific website, cookies cannot be and this makes it basically impossible to have cookies blocked for a general shield because it breaks too many websites I like to visit and am fine allowing some less strict cookie policy for.
Adding this option on a local shield would make browsing more secure in general for people who are willing to go through the process of unlocking cookies for specific websites only (just the way it does for the desktop edition) and adding just one more on/off switch there probably isn’t too much trouble.