It's not the biggest deal in the world but asymmetrical joysticks are better for the hand ergonomically
The natural resting place for your thumbs is higher up on the controller. On the Xbox and Switch controllers, The left side has the thumstick and D-Pad, and the d-pad typically gets much less use in most games, so placing the dominant input higher up is a more comfortable resting position for your hand
The right side of the controller has the face buttons and the right thumbstick which both have high usage and many games have you going back and forth between the two during gameplay. For pressing ABXY buttons, it's better to have them spaced out and higher up with the joystick placed below them. This is why the Wii U pro controller seemed goofy as hell. No other controller has you reaching your right thumb downwards to rapidly press the face buttons. Even the joycons are asymetrical
I've played tons of games on the DualShock 1-4 and the Stadia controllers just fine, but I prefer asymmetrical thumbsticks for long periods of play