PCB Pad sizes: Is it worth going over Level A of IPC-2221?
I can tell you that chip components 0805 and smaller can be rather difficult to hand solder when the pads are sized exactly to the chip for the purposes of reflow.

The reason is that when the pads are sized exactly to the component terminals, it can be tricky to have the iron make contact with both the terminal and the pad. You might inadvertently push the component a bit to reveal more of the pad but in doing so you shove the other terminal far enough that you can't make contact its pad anymore.

It really helps if you have hot tweezers where you can fine position the component to make sure both terminals are making contact or a hoof tip that is only tinned on the face and not the edges so it can hold a huge solder bead that can actually flow around and get under the terminal when it is a bit over the edge of the pad (but it still isn't always perfect).

And it can be extremely tedious with a chisel tip.

This is not an issue with other components though where terminals are exposed and low to the pad



Pad size matters even less for through hole since you don't need the molten solder to center the component on the pad during reflow or prevent tombstoning.

Small surface mount pads peel off really easily so larger pads help there but it is not really an issue with through hole though due to the adhesion of the plated through hole, the solder in the hole taking all the shear, and a pad/solder on one side of the PCB takes all the thrust force through compression reducing tension and peel of the pad on the other side.