Source: http://www.megalextoria.com/wordpress/index.php/2017/03/20/atari-7800-3/
The Atari 7800 really was one step forward and two steps back for Atari.
After the commercial failure of the 5200 (which was in part do to timing and in part due to some bad design decisions), Atari developed the 7800.
Read more: http://www.megalextoria.com/wordpress/index.php/2017/03/20/atari-7800-3/