* For that laptop I can buy Windows with Bitcoin (https://support.microsoft.com/en-us/help/13942/microsoft-acc...).
* I can book my holiday with Bitcoin (https://www.cheapair.com/help/payment-and-billing/what-is-bi...).
* I can donate to Wikimedia with Bitcoin (https://wikimediafoundation.org/wiki/Ways_to_Give#bitcoin).
Can't really do any of those things with tulips or gold. This is just a small set of places where I can do purchases with Bitcoin.
As for currency, sure a tulip has practical value. But does a $100 bill? You can roll it for a cigarette or it can give you 5 seconds of warmth if you burn it. But that's about it. The reason you have all your savings in $ or € or something else, is because we all as a society say "this piece of paper (worth less than a cent in materials) is worth $5, and this one $50, and this slightly bigger one is $100". Same with crypto-currencies.