The unicyclist on the left is saying the bicyclist is only riding a bike because they don’t have enough skill for a unicycle. The unicyclist on the right is saying they can’t learn to ride a bike because they’ve spent too much of their life riding a unicycle. It’s a dig at people who don’t want to switch to memory-safe languages like rust.

Sunk cost fallacy maybe?

I think it would be clearer if we saw the person on the bike pass by and the last panel was just the character laying on the ground