Depending on various factors..his target is between 45 and 60 minutes roughly but there are factors that can push a workout to be a it longer sometimes..
The question is...do they need to be? And for ONE muscle group? That is fairly excessive for a natural lifter for most normal humans.
If you are gifted genetically somehow then you are a rare person with rare recovery ability and combination of muscle fiber types.


Once you have achieved a physique tweaking it can take more time like your workouts suggest to bring up symmetry, etc.

Strength training requires longer workouts and all training regiments should have strength components. Jeff would agree with that.

Repeated hypertrophy experimentation has shown no increase in benefit for resting 1 minute vs 2. So decreased rest rime means decreased workout time as well. Some people however due to combination of fiber types and cardiovascular capacity benefit from a 3 minute rest period more Han 1, thus they will need longer workouts as well.
But in general, an hour should be plenty for most people.