Our little tiny leftover plica semilunaris is a vestigial hangover of the same thing. Tonsils are a bit like your appendix in that both are only ever removed because they've become inflamed and infected thereby presenting a hazard to their host: you.

Are tonsils useless?

Though small and seemingly useless, tonsils have several uses. The tonsils prevent foreign objects from slipping into the lungs. Think of them as goalies for the throat.

What are examples of vestigial structures?

Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the hindlimbs of the snake and whale. The human appendix is no longer considered vestigial.