Newsflash: currencies shouldn't wildly fluctuate in value. The fact that people use it like a stock market investment, (and an idiotic one at that, since there is no underlying business), is exactly why it has failed to be a currency.
Nothing's value fluctuates with itself. Money supply is controlled through interest rates in modern economies because it works better than directly controlling the money supply. Your comment betrays an unsurprising lack of understanding of the most basic concepts of economics. You're just parroting some talking points you've heard from techbros.
What does the term "wildly fluctuate" mean? In 50 years of USD fiat, gold vs USD has gone from 35$ to ~2000$ per ounce. That seems pretty rapid to me, since I can still talk to living people who experienced it
At least BTC has historically gone up, whereas fiat goes down, although only a few years of data for crypto compared to thousands of fiat, so maybe crypto will do the same as well