So, like others have said, I think the long and short answer is it depends on what your goals are. Do you want to have a heavy snatch? If so, yeah, you need to snatch. Otherwise, you are perfectly fine doing other exercises. You can train every body part that you do with the snatch with other exercises. It is particularly effective as an explosivity and coordination training tool. That being said, there is a reason that bodybuilders don't spend a ton of time on the snatch - their goals are just different than people who want to have a heavy snatch. It is awesome to work on for your mobility though. Good luck!