Most Bujinkan dojos don’t spar or drill with any level of resisting opponents.
I think there are several reasons for that.
A major one is how to start sparring without injuring their training partners or being injured themselves.
The Touch Drill is good for developing confidence in your distance management, power control, having strikes come at you, and trusting your training partners not to injure you.
I personally think drilling and sparring are essential tools for developing functional technique and skill.