If most people changed the default they would add steps to make it harder to change. Saying something an option is just a fig leaf if the company is allowed to tip the scales.

That's why a regulator can be effective. You can have a regulation that A has to be as easy to do as B and enforce it. Think of browser choice in on PCs in Europe or (briefly) the rule that it should be as easy to unsubscribe in the US as it is to subscribe. People have different feelings about regulations, but I think in places where everyone converges on a single platform pregulation that is protective of the individual makes sense.