Part3D when a sketch is already solid, in fusion360 or any other 3d model software, you are able to customize the length width or height by clicking or tapping the face of a solid object and extruding it or cutting it.

Although, yes there is that feature where you can edit the extrude height. But this will not work if you combined 2 or more parts and make xyz heights larger or smaller.

Having this direct editing feature would be much easier than going back through the history timeline to find and modify the original extrude. This becomes especially difficult when working on complex projects with a long feature history.

I hope i explained this better and makes sense.