As someone with dark hair and quite pale skin, I was basically a perfect case for it. At 7 sessions so far, the number of hairs that still grow on my face are countable - 43 of them by my count - I still do have to shave but it takes like 30 seconds because they're all focused on my upper lip and one particularly stubborn spot on my chin. The important part is that when I shave, I have no beard shadow at all now. I may not 100% pass yet without makeup but it makes makeup way easier to not have to also collor-correct for beard shadow.

Others have answered with more detail but yeah, it also does take testosterone suppression or you'll have to go back every so often to address any new/rejuvenated hairs. A cis guy friend of mine has to go just about every year.