I have more than anybody who has yet posted... split between 20 and 30 round mags.
To me, AR magazines are consumable limited life components. They fail... more readily than magazines for many other guns. They're also cheaper. It's easy to stock up. While a half dozen may last you for years they won't last forever. Once those feed lips crack or bend it's time to just toss it. I have no intention of being caught low on mags if mine break.
I figure I have more AR mags than I can use in several lifetimes. But then, I remembered 1994-2004 and prepared accordingly. If the day comes when I can no longer get a new one I'm STILL well prepared. I had these long before the current panic. The folks who just now realized they might want a good supply are just plain late to the party.