That's not true. There are several investments that beat inflation. In fact, the fortune 500 companies almost always beat inflation, and that's a relatively safe investment. Small business also has potentially much better returns for long-term investors while being somewhat more risky. Real estate is always a good investment because returns are almost guaranteed for renters. It's like operating a mini-business that takes up almost none of your time so that you can have another job along with it.
The metals market will not make you any money, they only keep up with inflation, they don't beat it. Silver might be beating it right now, but long-term it's really only a safe-store for value, not a big retuns investment. Metals are not accumulating wealth, they're accumulating dollars and keeping roughly the same value they had before. The only reason they keep going up is because of inflation.