In line with actual realistic gameplay, that's simply what would happen. Your character, being very speedy and dexterous, would be harmed by wearing armour. Usain Bolt cannot currently resist a bullet, but he is pretty fast right, throw some kevlar on him and he's less fast but more bullet resistant 🤣.
Let's see Glass Cannons make a comeback, perhaps def and dex have had their boring time farming stalemates and it's time to rotate back to 2008 meta.
You are thinking along the lines of both def and dex cannot be nerfed more than the other, why not? I don't mind defence taking a hit, if it mixes up gameplay and changes the current attacking systems boring nature. I'm high def, if I come against high def or high dex it's a stalemate, be more interesting if I also have to consider armour builds rather than just cold stats and a needle.