Cash is transactional, have enough for a few months of transaction necessities.
Crypto-currency is a niche item in a large world.
"For investment (not trading) purposes, it is clear that if the gold silver ratio keeps climbing, gold will outperform silver on a long-term basis. If you like precious metals to diversify your portfolio, you should buy gold and not silver."
https://seekingalpha.com/article/4338404-gold-silver-ratio-will-keep-on-climbing
Silver is an industrial commodity. It stopped being money 150 years ago. It's value as an industrial commodity overran the last vestiges of being a form of money in the 1960's. It's now a mostly overvalued commodity due to the distant memory of that ancient role.
Gold is the center of wealth. As the credit money backed by real people in economy is replaced by base money from central banks. The expanding base money of dollars is loosing it's utility as a stable reference of value. Gold moves to become the new base of value from which everything else is referenced. There will be bargains in tangible goods in the process of moving central bank reference point from cash to gold. But that opportunity remains a brief and very risky for cash holders who can't collectively move enough cash fast enough all at the same time. The optimum point of wealth preservation game theory as we transition has already been chosen, gold.