The question of which is a better investment, crypto or precious metals, is a hard one to answer straight up. The reason being not that they are too similar, but that they are extremely disparate, each with unique strengths and weaknesses.
The primary difference between the two is the level of volatility. Crypto goes up and down, often unexpectedly and with little warning. Precious metals on the other hand typically have a standard growth that is slower but less risky and more predictable.
Other differences include the price of investment. Newer cryptos or ones on a (temporary)downswing can have an extremely low buyin price whereas precious metals are, due both to supply/demand and the age old habit of "investing" in them, have much higher prices.
Buying and selling. Cryptos are easier to buy and sell, much faster as well with instant gratification on that front. This can be good or bad, depending on a number of factors in its own right.
Loss of assets. Precious metals are probably safer from a literal loss, your house and safe, or bank, would have to be physically robbed. While cryptos can be hacked, wallets phished, and wrong addresses used.
SHTF. In a "shit hits the fan" scenario both will become extremely devalued. The longer such troubles continue the more value they will lose. Despite the fact that in truly troubled times, think zombie apocalypse, gold and silver will be worth no more than dirt. As a whole though, cryptos would lose faster and in many cases be absolutely unaccessible. Due either to power loss or internet restrictions.
The short answer is that both have their own risks and rewards. The long answer is much longer than everything I have written here. The middling answer is that neither is necessarily better than the other, in my opinion anyway.
@erebus Certainly a hard question straight up. Always interesting to see in what perspective someone responds to the question. Appreciate your comment!