Not entirely true. There are many items that can be purchased with Bitcoins and other alt coins for that matter. Checkout this article:
https://www.coindesk.com/now-can-buy-mariah-carey-g-eazy-albums-monero/
I couldn't make a purchase with a baseball card like it was currency for an item. But I sure can with cryptocoins. Let's face it the whole darkweb runs off of bitcoin and other alt coins.
I don't think you can view it as collectible. I think you have to basically view it as a foreign currency.
Currency transactions are so fast with block chain and cryptocurrency. Say I wanted to sell my BTC right now, I could have straight cash money in my hand in 20 minutes. Now think about how long it takes to get money when selling a stock...48 to 72 hours till you have the cash in hand.
A coin is a coin is a coin. But the technology behind cryptocurrencies is what is revolutionizing finance.