You don't need to look from 90 deg angle. Satellites often times scan ahead/behind so they don't always scan at 90 deg angle.

Look at this image that is probably from a spy satellite. It's almost at 45 degree angle. https://www.thedrive.com/the-war-zone/29634/trump-tweets-int...

The previous post argued that the influence of the air is less severe looking straight down. If we now go back to looking at an angle, we are back to square one, the problem of distortion due to the amount of air between the observer and the observed.

If you need that you can send a drone though.