It's a lot easier to be more accurate with the right analog stick in the central position (the position it's in on the DS4 or XBOX controller.
I think it's easier because your thumb pivots over the analog at a higher position, so you end up with more control. You end up using the entire muscle, your thumb and tendon down to your tendon at the base of your wrist.
The upper position allows you to still move the analog stick, but you're using a smaller range of motion in your tendon/wrist. So that can be good for comfort, but less good for accuracy. So that's an explanation of the asymmetrical layout really, it prioritses control on the right side, and comfort on the left.
The problem with this layout though, is it assumes that folks don't use the d-pad, because having that at the lower position on the left side, is forcing your thumb into a less comfortable position, for an interaction style that doesn't require precision. D-pad inputs are simplistic, you don't need that wider range of motion that comes from having your thumb extend out from your hand to this lower position.
So, anything that uses a d-pad, just ends up being much less comfortable on an asynchronous style layout. It's especially true for the d-pad because unlike an offset analog stick, the dpad isn't raised to meet your thumb.
Because of that, I think that the DS4 style design is better for a wider range of games. You can play things like 2D platformers in absolute comfort using the dpad in conjunction with face buttons, and the analog sticks which tend to demand a bit more accuracy, are in a position that helps you achieve that. The compromise is, that if you're playing games that use the left along in the long term, you might find an asynchronous layout more comfortable instead. But for me, as someone that bounces between 2D and 3D games on the regular, the DS4 is just better for your hands.
Obviously everyone's experiences will vary depending on hand size and whatnot.