system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why so many walking based vehicles?

From what I know of engineering, walking based vehicles don't tend to make it past the planning stage, for many reasons. They're inefficient, they're prone to damage, they're unstable, particularly in combat situations.

Wheels or tracks are more simple and more reliable. In a universe which has those *and* vehicles that can hover, it seems silly that the empire's land forces are reliant on walkers.
gpt
A walker like the AT-AT was designed for one purpose only. Fear.

The exact same payload and armament could be installed on a hover platform. However the sight of something so big, lumbering towards you, the sound and feel of each foot as it thumps the ground passing through you, instills a primal sense of fear in an army. It's not just a tank coming towards you, but it is some unholy hybrid of machine and beast, hunting you down.

That fear goes a long way in wining a battle, and is an essential part of the Imperial battle strategy. 

As for why, you have yo remember that this is a civilization that has "solved" gravity and spacetime, and has done so for thousands of years. Litteraly anyone of any economic station, from the rich to the middle class to the dirt poor can own an hover vehicle. Ships that can fly across the galaxy in a matter of days are affordable.

The need to worry about the stability of a vehicle over uneven terrain is no longer nessasary. A self correcting hover gyroscope can solve that issue, and is standard on every vehicle. So a walker is no more likely to fall than a wheeled vehicle is to flip or a hover vehicle is to loose it's cushion.