This really could be listed as 6 things, since gold, silver, platinum .etc all precious metals, same category.

I don't consider investing in businesses as a safe investment. If someone was opening a restaurant, i certainly wouldn't want to invest in that, because a very high percentage of restaurants go out of business within the first year.

If a questionable government or rule of court ever wanted to strip you of your assets, people can easily make that difficult to do with crytocurrencies, and potentially with precious metals also. Other assets wouldn't be so safe.