Not to burst your bubble but assets with extreme volatility, like bitcoin, are not suitable for saving purposes. Investment maybe, but not saving. I assume "saving" purpose in this case means that it withholds its value while being easily liquidable.

If you on the other hand have a long saving window so you can tolerate huge swings in the price of the bitcoin (or other cryptocurrency) then the question arises why not diversify your investments like regular people and buy ETFs or other assets?

Maybe buying ETFs is harder than buying bitcoins, but in general the idea is (I assume) the same. However, what I feel most people are allured by with bitcoin is its random price movements where out of nowhere its price surges up and creates a total hysteria in the market.

I myself heavily dislike assets which price is mainly driven by emotional rationale and while bitcoin's idea may be good, I would not suggest anyone to put their savings in bitcoin. It would seem to encourage people to treat markets with magical thinking where the prices are set by otherworldly powers and not as tied to the revenue stream that is generated by the said asset.

Despite the crazy year, bitcoin still has less extreme volatility than some actual country's currencies. So for that small percentage of the world, bitcoin is a better "currency" too - besides for obvious things like local brick and mortar acceptance.

Sure but the de facto standard way of dealing with this issue is storing cash in a well-established fiat currency, like US dollar. Although I'm not sure what are you implying. I would assume buying US dollars is as easy as buying bitcoins in most cases. And more accepted too. The only problem being having to have either a bank account or physical notes somewhere stored.