Thanks for the wonderful article!!!! I also believe that crypto in general will eventually become more dominant than cash, BUT it has to be easier to use for the layman. Since I'm already technically inclined, I already own BTC and about 100+ alt coins, but I can't see "buying a cup of coffee" with BTC as the example normally goes.
On the one hand, it's VERY convenient for buying things of a higher value domestically and internationally, but it will NEVER replace cash unless there's an easy, low cost, and expedient way to make small transactions. Right now it's more of a store of value and a gateway currency to trading other cryptos.
I know that there are a lot of alt coins out there trying to solve the transaction volume, ease of use, and transaction fee problems, but we're not quite there yet. We're still on the bleeding edge of the technology in the early days.
If we want any crypto (including BTC) to replace current fiat, then a coin or whatever would need to have low transaction fees, confirm extremely quickly (in seconds or less), be easier to use than cash, and be able to handle more transactions per second than all of the worlds credit / debit card processors combined. Only then will crypto be able to overtake FIAT.... If you can explain to your grandparents how to use it, and they really get it, then whichever currency can do that (while being relatively stable) is going to be a success....
Right now, it's just not there.... If you want BTC you have to either exchange fiat for it, mine it, or be paid in it, the value can fluctuate quite a bit in the short term, and each transaction takes 10-30 minutes + to confirm. Additionally, if everyone is using BTC, then the transaction fees are high.... Can you imagine paying $12 transaction fee for a 99 cent cup of coffee? Don't think so... :-) Ethereum's vision is also awesome and 10x more capable than BTC, but the CryptoKitties fiasco proved that the network / protocol is still not strong enough to handle an adequate amount of transactions.
Right now I believe crypto is the future! It's an investment, but there will be a lot of volatility world shaking events, and churn before it becomes the next big thing. I think that there will be multiple "winner" coins and a ton of "loser" coins, but it's hard to predict the future on which will be which at this point!
Thanks for listening, and keep up the good work!