Not at all the same risk profile. Arc welding is just a really bright UV light, and without appropriate protection, it will cause what is essentially a sunburn on the surface of the eye. It is painful, but it usually heals in a couple of days. It shouldn't significantly damage the retina.

Laser light is different: a laser is effectively a point light source, and it will focus inside the eye to a single point with enough brightness to cause a burn. It can cause a permanent blind spot, and damage may happen faster and be less noticeable at first.

I mean like a bystander walking by a construction site who just happens to catch a bad reflection for a fraction of a second

yes, but not permanently. You can certainly get dazzled by bright headlights, I can anyway.

but laser light, like staring into the sun, will destroy the delicate structure of your retina, and it doesn't grow back.