The overhead forehand stroke is used most frequent because it’s the only stroke in badminton that generates the most power. The forehand stroke is used to perform the most powerful attacking shot, the badminton jump smash.
Besides that, the overhead forehand stroke is the easiest badminton stroke to perform. Most beginners learn this stroke first.
The next badminton strokes that are most commonly used are the underarm forehand and underarm backhand strokes. These are usually used for defence. They are relatively easy to learn too.