It's okay to use academic language if you're explaining it. If you replaced "intersectionality" with "flibertygoop" everywhere in your writing, would a reader still come out of it understanding flibertygoop? Then you're fine, you've explained the thing. That's particularly important for words that have many colloquial (or even formal) meanings, like socialism or anarchy, since it might already be flibertygoop to your audience.

It's also worth considering are how google-able the term in question is. If you start talking about intersectionality, that's a unique word and if someone trips over it they can find an answer easily. If you start talking about the absurd, you're going to want to name-drop Camus or something, since that's just a common word in English.

Finally, not every message needs to be accessible. If you can safely assume your audience knows the thing you're talking about, just use the jargon and save some time.