Possibly cost. But also suspensors only seem to give lift, or very small amounts of lateral thrust. All the pure suspensor vehicles we see move extremely slowly

Possibly cost. But also suspensors only seem to give lift, or very small amounts of lateral thrust. All the pure suspensor vehicles we see move extremely slowly. It's possible the 'thopters use suspensors for primary lift, maybe 80% of vehicle weight, and the wings are just for manoeuvring lift and thrust.