This is an important question about which there are several sections of Cicero criticizing Epicurus for not paying enough attention to it. I gather that the Epicureans did not admit that he omitted this, but that he denied the analysis being given to it by the logicians and asserted another approach to it that he held to be superior.
So this part quoted below may not be something that the ancient Epicureans admitted to "dispensing" with - but asserted that they dealt with in a different way:
categorization, logic, and abstraction are indispensable especially when communicating with others our subjective experience and the knowledge we get out of it.
So the challenge is to articulate the Epicurean counterpoint, and probably not to admit the approach to or the priority of these subjects suggested by the Platonists.