The leverage principle is key to providing many high-quality compound exercises (the major, multi-joint movements) on a single machine. So you get the most productive and natural exercises in a highly effective form. Presses, lifts, squats, rows and many, many more. Leverage permits the replication of natural angles of movement, provides balance and stability, and best of all, offers movable, steel-pin safety to prevent a load dropping in the wrong time and place. You can train seriously without an extra person in a safeguard role. Most so-called "home gyms" don't do any of this; they just provide largely isolation exercises - single joint activity - feebly.
By using major muscle groups, including major leg exercises, and great exercise variety, you can create circuit-style programs that can emphasise, pace, load, or intensity, so as to address all major fitness goals, ranging from strength, and size, to leanness and cardio gains. Powertec designed the original leverage home gyms 20 years ago. They've stood the test of time and have been frequently copied. All carry the highly-requiring European EU-957 standard for performance and safety. No others in NZ do.
In short, well-designed leverage equipment provides the power of free-weight training (for instance, rack, bench, barbell, weights) with the control and safety of a machine, in, very often, less space than a free weight set-up.