Fish are most certainly able to leave. They "just" need to swim fast enough in the right direction to move back along the hook, and suffer a little damage from the barb. Likewise with users, along the convenience gradient and disrupting their usage. Companies most certainly acknowledge this - they turn up the heat gradually so users don't jump out of the pot.

Your comment brushes aside this dynamic, in favor of a naive model where users don't succumb to path dependence or local maxima. Why?