Omega-3 is an EFA
My bad, "I'm not a scientist" bit me hard here lol, though I did read that if you get your omega-3 from plant sources (linolenic acid) its absorption rate is extremely low comparing to sources like salmon.
Regarding supplementation, I feel like having to do that because of inherent issues with your diet is somewhat of a dirty hack (I do take some supplements though, so I'm not gonna pretend like it is not an option).