Probably because it’s so disappointed at how Scientific American has declined.
The only other magazine that I miss as much is old-school Byte.
I would add Nat Geo to that list, given one has an interest in our planet, peoples, culture. I had subscriptions to these given to me as a kid and enjoyed reading every one of them. It was like a part time general education course that I really did not appreciate until roughly a decade after it was all over.