[Question] Why didn't infantry tanks work? - eviltoast

It seems to me that in the interwar period there were a lot of tanks designed with the idea that they would stay with groups of infantry, providing direct fire support while being a lot more durable than a field gun. My understanding is that this was generally abandoned in favour of faster tanks which operated somewhat independently of infantry. But to my very limited knowledge, the infantry tank seems to make sense. What were the theory’s disadvantages? (Or is my understanding flawed?)