3- till now, Bitcoins and other cryptos appears to me not as currency but as a bullion of gold, a bullion of silver, a bullion of platinum, an ingot of aluminium. It costs money to buy and keep, and it costs money to spend.
nearly 1 billion dollar yearly bitcoin payments/transactions only through BitPay disagrees with you:
https://blog.bitpay.com/bitpay-growth-2017/
it doesn't get any currency-er than this.
Thanks, the link you posted I just read so quick, what it says is simply bitcoin adoption, use.. etc is growing and it is here to stay.
The point no. 3 is simply as follows:
How much would it cost you to pay in BTC only 10 cents to someone?