Ummm, don’t we already have multiple multi-$Billion satellites in low-Earth orbit for the same thing??
Something’s not passing the smell test.
Can't detect low-flying cruise missiles in real time with them.
Despite the nonsense you see in the movies, with a low-earth satellite at best for any given spot on the ground you get a brief (minutes long) look at it every few days. Even a huge number of satellites still only allows you to see a given area part of a day. You don't get a continuous movie.