I think Bitcoin can be seem as more stable than some fiat currencies...
The thing with Bitcoin is that there is no central government that decides how much to print of it, so at least that part of the equation is not volatile at all.
Other currencies have that volatility, which depends on the government.
This is the point I try to make sometimes. Bitcoin has really matured enough to the standards of other top fiat currencies to an extent in terms of its stability. As for the volatility, many fiat currencies around the world do experience volatility too, maybe reason why people are not so concentrated in them is because most individuals are already used to the money and are using it domestically, so they might not really know it's worth and value history, or care less.
I will take Naira for instance and how it has fluctuated over the past year. Within last year, Naira was around 800 naira per dollar around January 2024, by September the same year, Naira hit around ₦1,600 per dollar, by October the same year, Naira was around ₦1,650 per dollar and by November, it saw it's highest fluctuations hitting almost ₦1,700 per dollar and now it is around ₦1,530 per dollar. This is an example with just Nigerian Naira to dollar exchange rate.
I know there are countries whom have experienced worst volatility especially within the African continent, but reason why many aren't talking about it is because these currencies are not worth anywhere close to Bitcoin and such fluctuations might not see any drastic change in prices like a bitcoin will, particularly at individual level. Hence the reason why the talk have been centered on bitcoin but the fact that Bitcoin isn't the only currency that can experience either short term or long term volatility cannot be overemphasized.
...Is that they are altcoins?
Seriously, I have seen enough altcoins to know one thing for sure, nothing is ever going to come as secondary to bitcoin. They are all shitcoins created to make the creators rich unlike bitcoin whose creator decided to go underground.
Any coin declaring itself to be the next "bitcoin killer" is a FAD. No such thing will probably come in the near future.
There is nothing like 'Bitcoin killer' and there would not be one anytime soon. No altcoins have shown any trajectory or market potentials to beat bitcoin anytime soon. My fav used to be Solana but Solana has given too much access to shitcoins that have influenced its growth negatively, although analysts say it will help the coin grow in the future but for now, no coin has shown that prospect or prosperity to kill bitcoin or anything of such.