A plate armor still weighs 65 lb and that will affect carrying capacity of all creatures who have dumped their strength.
BG3 has a carry capacity calculated a 15 per point of strength...a character with 8 strength can carry max of 105...put that heavy armor on along with the weight of your other equipment and you can carry nothing other than the gear you equipped. It definitely doesn't incentivize characters with low strength to wear heavy armor.
