It's too low to open a parachute, and it's only barely tall enough to fly away from. When you first step off of a cliff, you aren't moving very fast so your control over your trajectory is relatively limited. Once you've fallen for a bit, you can transfer your speed into flight.

When people started jumping off of cliffs with wingsuits they needed the cliff to be sheer for a thousand feet or so before they gained enough speed. There aren't all that many places with that sort of cliff.

However as the technology has increased, that requirement has decreased drastically and now we're getting to a fairly ridiculous point where they seem to be jumping steep hillsides rather than cliffs. It's starting to get to a point where any little steep bit on top of a mountain is enough to start the flight, which means that more and more locations are being opened and more and more unique terrain is being flown.

This is the most extreme example of this that I've come across. This cliff (if you can call it that) really requires perfect technique to not die on. There's pretty much no room for error.