Yes, Stockfish is genuinely impressive. I would be proud to author Stockfish. You don't think so?

As a developer yes, especially given that it runs on a PC, and DeepBlue in it's day was really more impressive since is used custom ASICs.

But, I assume the Stockfish developers aren't comparing themselves to Magnus.

Let's see if OpenAI, or someone else, can get these sort of physics/math results out of a desktop PC - that would also be an impressive piece of engineering!