Also I really don't understand why staggered joysticks are the standard.

In case you were actually curious, here is the reverse timeline:

• Staggered joysticks are the standard because Microsoft Xinput is the standard.
• Xinput is the standard because for about a decade, it was the one controller interface that actually worked without issue for a lot of people.
• Microsoft controllers worked for a lot of people on PC because Microsoft controlled the most popular console and the most popular OS. Sony and Nintendo had no interest in supporting their controllers for PC.
• Microsoft maintained a similar controller layout to their original Xbox console.
• The original Xbox controller was designed before the advent of popular dual-stick games (the first of which was the original Halo). At the time, the right control stick was seen as a secondary control for the camera in third person platformers (see also the c-stick on the Gamecube).
• The original Xbox controller design was cribbed from the Dreamcast, which was to-date the nicest and most ergonomic controller. The Xbox design added the second control stick below the buttons.

Also of note:

• The only other dual-stick design at the time was that of the Playstation, on which both control sticks were secondary, an afterthought not even present on the original PS1 controller. Making the left control stick "primary" was progress.
• Nintendo briefly ended up in the same boat as Sony, when they added secondary control sticks to the original SNES design to create the Wii Classic Controller.
• The only controller that tried to make both control sticks primary was the Nintendo Wii U, which unfortunately failed for unrelated reasons. I had one, and the symmetry was glorious, for those few brief years.
• Nintendo relented and went with the staggered design for the release of the Nintendo Switch, on which the asymmetry was necessary in order for both joycons to also be able to function as separate controllers.