I actually think ascent, is not over-emphasized, but instead, misinterpreted and isolated to thinking of it as just tree access.
Vertical movement takes massive energy so unless you are doing a simple, up and back down procedure, like a simple removal, vertical movement will happen over and over again, throughout a work climb.
System efficiency needs to consider the entirety of the climb. Having a system that will change between ascent and descent quickly, while still utilizing leg strength, should be a large part of what we are looking for in a system.