You can look up what the acronym AESA means without unstanding it.
Take two speakers that are next to each other. If they emit a tone of the same frequency, the sound will “add up” and be louder in some directions, and cancel out to some degree in others.
A phased array radar uses the same concept, but now on electro magnectic waves, instead of sound waves. And with much more than just 2 emitters. By carefully choosing the phase of the signal in each emitter, itnis possible to both choose a single direction that receives the strongest signal, and to tighten the spread around that direction (creating a pencil beam). This is what the dish is for in standard radars.
If these phases can be fully controlled electronically, you can steer where you are looking, and swap between wide and narrow search beams in an instant. However, that is not a trivial thing to produce. So cheaper phased array radars use mechanical systems, or partial electronic steering (example: only horizontal steering).
I agree with that. But that is not a conclusion that should be drawn from the article. Hence my reaction. If anything, the article shows a prime example for why we should spend all those trillions.