Do I need machines or free weights?
You can build muscle with either. Free weights are useful for coordination, loading freedom, and specific strength skills. Machines are useful for stability, target-muscle focus, lower setup complexity, and pushing heavy sets with less balance demand.
The better choice depends on the goal, exercise, body, skill, and equipment. A barbell squat is not morally superior to a hack squat. A machine press is not automatically less serious than a dumbbell press.
Use the tool that lets you train the target safely, progressively, and consistently. Most good programs use a mix.