Laser hair removal is permanent. The issue is that it’s not 100% effective. It doesn’t matter how many times you laser, some hairs always survive, and they will keep growing. But the ones it does zap stay zapped.
Electrolysis has a better hit rate for making hair follicles stay down, but if you’ve got dark hair, it’s much slower to receive electrolysis than it is to receive laser.
I’ve only ever had laser hair removal on my face, the tiny amount of hairs that remain are manageable with tweezers.