is wisdom tooth extraction always necessary?

Hello board, last year I had and exam.  No cavities, got a full mouth x-ray and discovered that I had wisdom teeth.  I had no clue.  None had come through my gumline.  Not having health insurance paying out of pocket for any and all medical needs is expensive to me.  Anyways, just this week, I had a sore cheek and noticing my pesky wisdom tooth had come through my gumline.  it's half exposed, no gum swelling just a bit of jaw soreness.  My question is, is it always necessary to get your wisdom teeth out?  It's a mild discomfort to me, but I'm not suffering.  Suffering more from worry than anything.  Here is my X-ray from last year, it's the left tooth on the upper jaw.  Thanks everyone.