we should know that bitcoin is volitile.
There is no denying the fact that Bitcoin is volatile, it is yet to attain stability, but we could see that in the coming years, remember how old Bitcoin is by the way. Fiat currencies are also subject to inflation, and quite a lot of them lose a lot of their value, especially currencies of underdeveloped countries, it does not make them any less of a currency, does it. If you look at most fiat currecies from three years ago till now you'd see how much value they have lost to inflation; a product of the pandemic, printing more money, etc, Bitcoin on the other hand plunges based on supply and demand factor, FUD, etc. So that is it, different kinds of currencies, with different characteristics.
A saves $1000 in another currency like Euro, from last year till now, even if euro depreciates, he will still see at least $950 worth of it. But this cannot be said when someone got $1000 worth of bitcoin when bitcoin was $62k. By now he should be seeing $350 or so.
I wish you can understand what I meant. So, Op is write that bitcoin can make one cry if you do not observe it. And it can also make you rich.
The thing is this, all of this is caused by volatility, and anyone who uses or plans to use Bitcoin must know this, they have to do their own research, i do not know much about the inflation levels in Europe, but if i am to use my country as a case study, and use cooking gas as the example in my case study, right now we are paying twice the price for a kg of cooking gas compared to what we payed last year, that is inflation, the cost of living is up here, and the value of our money has reduced. That is somewhat the same scenario with Bitcoin volatility, do not also forget that we are talking about fiat currencies that dates back to many years ago, and Bitcoin that is a relatively new currency.
If I want to buy a car with bitcoin, and save my whole bitcoin to get the car and I couldn't get it today. By tomorrow on getting to the car shop I discovered that my bitcoin is down by 6%, I will not be happy. No currency does that. So, in as much as volatility is in bitcoin, it cannot be seen 100% as a currency.
It is 100% a currency cause it is a medium of exchange, of course you just said it is possible to purchase your car with it, every other thing like its volatility is part of its downsides, which every currency/medium of exchange has.