MLMs cost a lot. While they can build up self esteem, they also tear it down in other ways. People here who were in them have taken years, in some cases, to recover emotionally. There are many other ways to build up self esteem. One thing I did a while back was to take on one of the scariest challenges I figured I’d ever face. I’m a serious klutz so I started taking ballroom dancing lessons. I’m actually getting compliments that I’m learning how to lead quite well. It wasn’t a quick change, but it makes me feel quite good about myself.
There’s also other self help groups just tackling things you want to learn and aren’t sure you can, or groups like Toastmasters.