Do you think we will be able to use BTC in a couple of years to buy for example coffee?
It will be done when it needs to be done. And it should be done the right way. The tech already exists (Lightning Network). Currently, it's not necessary, as coffee can be bought with $, , £, etc., that everybody has in their wallets. Buying coffee with BTC doesn't solve any problem at all. There is no need to do something right now, just to prove something. It will be done when it needs to be done.
There are also different kind of bitcoin credit cards available or coming soon. this should boost the daily use of bitcoin like buying coffee.