[falcolas]

Boiling something is more about pulling water out than it is finishing the food. But it's definitely one of the corner cases - for the reason you mention: the temperature increases are small.

But temperature for boiled things is still important - see candy for example. The temperature directly indicates the amount of water left in the mixture.

All that said, resting is a distinct step from heating that is often required for a food to end up as you expect it to. IWO, yeah, food isn't always ready to eat after heating.