Admittedly, most people today only use bitcoin as an investment, very few use it for payment purposes. But that doesn't mean it deviates from its original purpose, you can still use it as a payment method if you want regardless of what other people use it for. Just like gold was used as currency in the past but over time it has been used as jewelry, investment or store of value...is gold straying from its original purpose?
Bitcoin is still Bitcoin, the only difference is that people use it for their different purposes.
If you consider bitcoin as just a currency or payment method then you are right in saying that bitcoin is overvalued, but if you consider it as an asset, an investment. You will find that bitcoin is still quite cheap compared to what it gives us.
As far as I know, Gold has unique properties; you cannot simply replace gold by another metal when you really need gold. The value of gold goes beyond its beauty; it is useful, it serves many purposes. On the other hand, Bitcoin does not work like this. And I believe it will soon be considered
fools gold if it continues in the path it is taking. There are cryptocurrencies that are not Bitcoin (a.k.a. gold) but is capable of doing everything it can and better (a cheaper/better gold?!). One cannot replace gold, but one could easily replace Bitcoin by something equal or better.
That is the danger.Silver cannot replace gold nor gold can replace silver, because each one has their unique properties. If silver could change its color and copy all the qualities of gold and yet retains its unique properties, which one will you buy?! Why buy gold
and silver when I can simply have both in a single metal?!