It seems like it's absolutely possible to solve all of the unrealistic problems that exist in CRPGs. You could have a rational encumbrance system, where you can only have the armor you're wearing, minor supplies in a backpack, and everything else has to go on a pack horse. You could have realistic hit points, where a solid hit from an enemy with a sword meant very rapid death from blood loss or organ damage, hits on armor did nothing, you got physically tired quickly and had to actually rest to feel better (ever done HIIT training?, like that), and when you were exhausted you just collapsed and got stabbed to death. They could have realistic movement speeds, where trying to walk across a kingdom would take a month in real time.
But would it be fun? Would anyone want to play Medieval Minor Nobility Life Simulator?