A young man would still have new hair growth scheduled until around 25 years old. However, had you have electrolysis, you would be seeing much less hair, because with the right practitioner, you would have caught up to the growth phase, kept the skin bare, and only the new growth from follicles that previously grew no hair would be coming out now.
As for the other question, should you continue when you see no results. Well, those who give guarantees usually say, "Pay us a certain amount of money, come in on this schedule, and we will give you free treatments once every 3 months if needed up to a certain date, (usually 2 years after the first treatment) after which, you are out of luck." How does that guarantee make you feel?