It is true that Kant sought his foundations in apriori categories. But this should be interpreted epistemologically, not psychologically. What we can learn from this is that we need some way of making sense out of sense experience. You question the logical requirement. Well, Kant's logic is not your usual sort, but in its simplest terms it starts with the essentialist notion that we need both form and content to experience anything.
Form is what provides coherence and imparts order.
Coherence and order are logical constructs. From experience we cannot arrive at causal connections. For all we know, the world came into existence 5 minutes ago and will disappear five minutes from now. With no sure footing, Hume relied on belief. Kant, taking a different starting point, came to the conclusion we can know things.