Why do I need to give full disk access, this make no sense.

You don’t have to click accept, but that is the only “workaround” to get rid of the popup. Otherwise it will likely ask you every time you open Illustrator. I’ve read reports of it still popping up despite granting full access though, so do with that as you may. 

As I understand it the request for full disk access is actually coming from Apple not Adobe. It has to do with third-party programs getting access to protected system folders on the Mac. Whether the process could allow Apple to access private files seems to me to be a question best asked on an Apple forum.

It’s always a tradeoff between functionality and personal security, but I strongly suspect that Adobe isn’t interested in files on your system covered by NDAs. Unless they’re created in Adobe applications, that is. Then they want to make sure that working with them in said Adobe applications are seamless and effective, and that you can get the results you expect when you use Adobe software.

There is no current, supported version of Adobe Illustrator that isn’t going to make that request to offer you full functionality from the software.

Sorry I don’t have any better news for you,

Randy