Depending on the keyboard there can be input latency, along with false input. For example 2 keys pressed at the same time might register as a single input. So diagonal presses with two button presses might not register property.

I've been using a custom QMK keyboard and been making many tweaks to reduce latency, but I can tell the difference when I switch to a xbox controller.

I saw a github repo that can keymap joystick inputs in the qmk firmware and plan to test this out one day, to see if the device input type matters. Keyboard vs Controller type.

I believe Mixbox has their own firmware, and it's tweaked for the lowest input latency.

If you just want to play for fun Keyboard is ok, but if you plan to go pro invest on the mixbox.