So is "something solid" potentially worthless. Anything is worth what someone will pay for it, period. Gold used to be rare and with an aura of worth, the same as other precious metals. They no longer are nor are diamonds. Their values are artificial, just as the dollars.
Remember, something, anything, is worth what someone will pay. The dollar is backed by the U.S. government, whether you trust them or not, and today we are still the most stable, the strongest, and the most dynamic economy in the world, despite the best efforts of the Democrats and other leftists. Therefore the dollar is sounder than any alternative.
At one time we said that a dollar was worth a certain amount of gold. Now we say gold is worth a certain amount of dollars. World wide trade, especially considering the population of the earth today, makes a gold standard impossible to reestablish nor would it be as flexible as today's dollar.
The danger is in the Fed tampering with the money supply increasing or decresing its worth, as the case may be. And I'm not certain what I'm getting for a dollar's worth of the full faith and credit of the US government. There certainly is no correlation that I can discern between the worth of the dollar and the worthiness of the US government.
When a dollar was redeemable for an established amount of silver or gold, you knew precisely what you were getting.