Even with great technique, it’s not as simple as “strength”.
Even if we suppose that the heavier guy can lift more weight in the gym, (very questionable assumption but that aside), even if we grant that assumption, that doesn’t mean they can move a light weight like a racquet faster.
People have studied about fast twitch and slow twitch but there may be a bigger mystery re maybe some more distinctions like maybe there are fast twitch for smaller weights and fast twitch for heavier weights.
At one point some years back , at about 36yo I was squatting a crazy amount. Well over twice my bodyweight. I did a lot of reps at 2.5x times it. And I was about 68kg. I should probably have paused the badminton and signed up to compete in a squatting competition! I don’t think it made me fast though. Even if my badminton technique was better, I still don’t think my leg speed would have been particularly good. It’s a different type of strength.
In badminton they just call everything strength. A player has better technique? Look at the strength! A player is fast? Amazing strength. A player has good endurance – what strength!
