If you are looking to increase strength, muscle mass, and general function, you can pick whatever exercise you prefer…whether they are machine or free weight based. But specificity of training is a thing. Machine squat will absolutely help your barbell back squat to progress, but if you want your back squat to be as good as possible you better be doing some back squat. Same in reverse. Comparing something like a leg extension to a barbell back squat and then saying the back squat is superior is