Hehehehe, you silly adventurers. You forgot a very, very, very important point. You always do.
I have more magic items than you. I am higher on the Wealth-by-Level chart, and I have the Wisdom to know that I need to use them. Even better, I NEVER have to go shopping. Over the centuries, countless tasty treats have showed up on my doorstep and fed themselves to me, and those yummy snacks have always had a pile of magic items. Every one of those would-be tarrasque hunters was loaded with a veritable Christmas tree of magic items and I've taken my pick over the centuries.
OK, OK, I'm not so good with reading scrolls or using wands (except when I swallow them whole!!!) and I've never found a magic sword that's better than my own armored teeth, but I have tons of other useful tricks. Ever seen a tarrasque on a flying carpet? Weeeeeeeee!!!!
I have 217 rings of invisibility. I only ever wear one of them, of course; I had a jeweler in some village I ate weld the other 216 of them into a charm bracelet for Mrs. Tarrasque (right before I ate him). I have a +5 Cape of Free Will and a +6 Headband of Mental Superiority. I have a necklace of continuous Prismatic Sphere and wear a belt of continuous Dimensional Anchor.
If you can name a magic item you don't want me to have, I have it.
So bring it adventurers, come to me. I hunger!