Get an issue of Scientific American from the past few years and compare with one from the early 90s. It will become obvious why Scientific American no longer has readers.
The Atlantic went the same way, but as more mainstream magazine, that's kind of okay. Not acceptable for SciAm.
For example, they publish this, now:
"The Revelatory Cringe of Anthony Fauci"
https://www.theatlantic.com/books/2026/07/anthony-faucis-emb...
Which, regardless of what you feel about Fauci, is at least against type for the Atlantic. But in 2020, they had no problem publishing garbage like this:
"Georgia's Experiment in Human Sacrifice"
https://www.theatlantic.com/health/archive/2020/04/why-georg...