Some time ago I invested in gold and raised decent money but with cryptocurrencies of course income can`t be compared, because here in a few minutes you can double your contribution, and with gold this will not works. From beginning I was training on trading, there was a time when I didnt understand anything and poured all the money, but then after some time when experience was more than it started to earn and was able to repel what was poured out at the beginning. You can also invest in real estate, I didnt try it, but acquaintances already are engaged in this for a long time and sort of like successfully.
You can leverage your earnings with gold too. You can look into gold futures and options if you are not quite happy with plain gold. Bitcoin as well as other coins have been able to offer quite hefty profit opportunities recently, but once the market is saturated, they will be gone. It may take years or it may happen tomorrow but we will get there eventually.
Investing in solid companies in the stock market is also a relatively safe approach especially for larger amounts.
You can live off dividends but you should invest huge amounts of money in the stock of these companies to make these investments pay off.