Generally the more advanced you are as a lifter the less specialised machines are going to benefit you. Machines are there for people who don’t know what lifts to do and how to do them with proper technique.

If you glimpse inside the gym of a professional athlete you’ll generally find a comprehensive set of dumbbells, some Olympic bars + plates and a bench and not much else!

On the other hand, barbells are great until you realize you're missing some critical stabilizer and that is why your shoulder or glute has been hurting for years. Then you would kill for a cable machine.

Personally I think smith machines and cable systems are pretty handy for bodybuilding - mostly because they help you isolate certain muscles in a way you can’t do with barbells and dumbbells. Or they allow you to do things like weighted lunges or shrugs or tricep exercises at high weights with much less risk of injury vs doing them with free weights.

Plenty of examples of elite bodybuilders training with them.

Sorry but this is not completely correct. Many expert bodybuilders use a variety of machines to train each muscle group.

Power lifters, however, tend to focus on the compound movements and therefore probably need less equipment.

> Machines are there for people who don’t know what lifts to do and how to do them

That’s an overly broad generalization. If you look up pictures of Arnold Schwarzenegger’s home gym, it’s mostly machines.

I can probably make some space for a home gym, but like I said earlier part of the motivation going to the gym is to see other people working out and being serious at it. I am no longer an advanced "lifter" because of certain injuries and disorders that were diagnosed but I do LOVE the stairmaster at the gym and it is best for my health problems, and that kind of equipment is not something you can easily keep at home (you need a tall ceiling too), so I do need specialized machines in that regards. As far as weight training is concerned I can probably survive on a home gym.