I'm hoping the next edition will make armor and shields a bit more complicated again. I also don't like how investing in 16 Dex doesn't give you any defensive benefit with Medium Armor and you're better off with Heavy anyway.
Well... it's useful when you take the "Medium Armor Master" feat into account, since that feat allows you to apply a DEX mod of +3 instead of just +2.
But yes, the armor system is overly simplified and was much better in D&D 3.x.