First of all for now, 30 cents worth of BTC was enough for me to get confirmation approximately in 10 minutes. Also, such things as LN are designed to simplify such "coffee transactions". And this solution becomes pretty popular. The other question is that why should you pay those $2-3 in BTC while there is a chance that tomorrow it could become a $4 worth of BTC? At this point it seems much easier to pay in cash.
Aside from fees, we are right now in the speculative fever so why waste your Bitcoin just to have a coffee? I would rather hold my small bitcoin and see where this bull run is going to. And yes this is the problem on the currency side of bitcoin people are not daring to use the bitcoin just to buy anything and on the side of the merchants they can be disappointed to realize that not many are actually using bitcoin to buy something from them. Is there a solution to this? There is and that is to make bitcoin not volatile but the problem is how to make it like that...any idea?
By the way I'm sure that solution would come by itself.
We just need BTC to grow and increase its market cap. Then from one point it would be less volatile and more stable so we could use it without warrying that tomorrow it would increase in price. This is just like attempting to change the price of a coin with $1bln MC and a high volume and $1k MC and small volume: in 2nd case even 100$ investment may multiply its price while in the 1st case even 1000$ would have no impact. The same thing gonna happen with BTC at one time.