it’s just something we didn’t think was possible being proven possible.
The theorem was proven thousands of years ago, I think it’s the particular method didn’t seem possible to be used to prove the theorem. Specifically much of trigonometry uses the pythagorean theorem as a foundation, so the fact the proof was constructed without needing anything that depended on the pythagorean theorem is what was difficult. Definitely a cool start for a math career, it’s generally how mathematicians approach math research, i.e. the proof being the the focus even if a theorem is established. I doubt it’ll be revolutionary by any means, and it’s annoying for media to sell stuff like this, it is extremely impressive to do this, and especially as a high schooler, even if there isn’t some quantifiable impact.
Pythagorean theorem has over 100 proofs, they are just geometric one, this is the first trigonometric one. The reason it is impressive is that the pythagorean theorem is foundational to trigonometry, so any attempt at a trigonometric often calls on the pythagorean theorem implicitly.