A teacher's default response to a student's difficulty — solving the problem for them versus helping them build the capacity to solve similar problems themselves — has consequences that extend well past the immediate lesson. A highly directive teaching style can produce excellent short-term results while leaving students less equipped to handle setbacks independently, since the student never practiced the actual skill of working through difficulty without external rescue.
This is a subtler distinction than simply "good teacher versus bad teacher" — both approaches can produce technically skilled students in the near term. The difference shows up later, in how each group of students responds when a teacher or mentor isn't there to immediately resolve the next difficulty they encounter.