Known downsides of small colliders physics

Godot Version

4.2.1 stable

Question

I’ve been coming across some collision problems with characterbody2d so I was testing out by changing the size of the collider but it’s still hard to tell whats the problem exactly.
Does anyone know whats the downsides of having a very small character versus a bigger one? For reference my characters collider was about 2x8, now I’m testing it with a collider thats 16x38. Thank you