The issue is not the genre “single player (shooter)” itself, but that these big companies just churn out the same generic bullshit and then act surprised when no-one plays it.
AAA studios just don’t have the balls anymore to take a risk and develop something unique. And this is their downfall.
Titanfall 2, Metro Exodus, Ghostwire Tokyo, Doom (to name a few) are all excellent first person shooters. All of them have something unique about them that makes them worthwhile.