Try Taking a Sticky Note Off the Pad With One Hand
Go and try it. Put a pad of sticky notes on the desk and take the top one off using one hand only.
The pad slides. It travels a few inches across the desk, or it lifts and flops, and you end up pinning it with your other hand. Which is fine, unless your other hand is holding a phone to your ear, which is the exact circumstance in which you needed to write something down.
Why this is worse than it sounds
Sticky notes exist for one reason: catching a thought before it disappears. A phone number said once. A room number. The name of the person being transferred to you. Their entire value is in the two seconds between hearing something and it evaporating.
Anything that adds friction in those two seconds defeats the object. Hunting for the pad, wrestling it flat, hunting for the pen. That is why people end up writing on the back of an envelope, then losing the envelope.
The fix is a notch
A holder solves this with weight and a shape. The pad sits in a base that does not slide, and a cut-out notch at the front gives your thumb access to the top sheet's edge. Press and pull, one hand, no chasing.
The secondary benefit is that the pad stops migrating. A loose pad drifts around a desk all week and ends up under a laptop. A pad with a fixed home stays where you last looked for it, which is most of what desk organisation actually is.
Ours is a warm brown holder about three and three quarter inches square, taking standard square memo pads, with the notch cut into the front face. The design is licensed from Hpinvent.
Two things worth knowing. It is sized for square pads, so the long rectangular ones and the tiny page-marker sizes are not what it is cut for. And it is a dry desk piece, which is to say do not use it as a coaster, however conveniently placed it turns out to be.
It sits in the same warm brown family as our pen cube and catchall tray, if you are assembling a desk rather than fixing one problem.