Outside of hiring and firing managers, I'm not too sure there are areas where Brands doesn't have full control here. You could of course argue that he should have control of that element too but as the owner, Moshiri may feel that the appointment of crucial resources at Everton (like the manager and DoF) are the responsibility of him and the Board and although I wouldn't agree with that, you can't really argue against it.
I would say, and I think many would agree, that recruitment is by far our biggest failing and all of our other problems are spawned from that. Brands, as the Director of Football, is completely responsible for that, just as Steve Walsh was before him. He has failed, by and large, at bringing the right players in and moving the right players on. We have somehow come within a whisker of falling foul of profit and sustainability rules, as if no one was keeping an eye on our accounts, which again points to total amateurism from his Department.
Whilst you are certainly correct that firing Brands wouldn't fix the club completely, I think that everything that falls under his remit is under-performing and he has to face up to that scrutiny.
We need to fix one problem at a time to put our club back on track. One of our problems, in my opinion, is that we have a poor Director of Football and we should fix that problem.