Not that it matters much, but it seems to be somewhat unclear who came up with the idea for the superheterodyne receiver first. Could be Armstrong, or Lévy, or even Schottky. The patent in the US was eventually awarded to Lévy.

Armstrong definitely was a genius though. Before the superheterodyne receiver he also invented the regenerative receiver.

And you're right, the superheterodyne is such a marvelous technology. The principles it's based on aren't super complex in itself, but the combination of them is genius.

https://en.wikipedia.org/wiki/Regenerative_circuit https://en.wikipedia.org/wiki/Superheterodyne_receiver