This is true, but the bottom at which people value bitcoin continues to rise significantly over time. Yes there are crazy bull cycles and bear markets that make the price highly volatile, but even people who bought at the absolute worst time 3 years ago, at $20k, before the price tanked by 80%, are currently nearly at 150% profit.
The price continues to be volatile yet less and less risky and overall trending upwards.
Please stop telling nocoiners this arcane and forbidden knowledge! Instead, encourage them in their belief that Bitcoin is a scam, a collective delusion, a market mania, a bubble, based on nothing, wastes energy, will go to zero, and so forth.
When, in a decade, 1btc == usd1M, we'll all be grateful that such people stayed out of the market long enough to allow us to buy more bitcoin relatively cheaply.
What they can't see is that Bitcoin is now more likely inevitable than not.
The usual fallacy is when proponents claim that Bitcoin is the only asset able to escape inflation due to fiscal policy interventions. This couldn't be more false. The very definition of inflation is an increases in prices, or a decrease in buying power. However, investors have been buying assets and investments to avoid inflation long before Bitcoin was even invented.
Bitcoin isn't a particularly good store of value because the price is driven purely by demand, which is currently in a state of market mania. It's not even the first market mania around Bitcoin. Past bubbles were also met with a "this time it's different" attitude before the inevitable sharp losses.
Bitcoin has value not because someone coded a 21 million coin limit in the code somewhere. Bitcoin has value because people want Bitcoin. Why do people want Bitcoin? Because the price goes up up. Why does the price go up? Because people want Bitcoin. As soon as something breaks that cycle, it doesn't matter what the maximum number of coins is. Without demand from the belief of future increases due to increasing demand, the price will go down. The purchasing power decreases.
Everyone likes to demonize fiscal intervention, but the reality is that counter-cyclical fiscal intervention tends to benefit the average person. Running inflation too hot is bad, but swinging to a full deflationary currency (Bitcoin) would also be bad for the economy.