How can 7 tps will survive the mass adoption?
It won't. Thats the reason the lightning network is in development. The LN will scale to 10k+ transactions per second.
Anyway nobody is going to pay for cup of coffee in bitcoin if 1 confirmation take 10 minutes.
You don't need to.
It is safe to accept 0-conf payments for low value payments (e.g. a coffee), especially if you are buying it physically (not via internet).
And in future you also won't have to since the lightning network will allow instant payments.
I guess you have a few seconds to wait, from payment until you coffee is actually done? Because in this timeframe you can do multiple payments back and forth, all
confirmed.
Apart from mobile phone apps, I guess some kind of Credit Cards by reputable bank also may come into picture iff for instant transactions
iff => If and only If Bitcoin is mass adopted for daily purchases.
Using Credit cards (issued by a bank) would destroy the whole purpose.
If you insist on using a plastic card + trusting the screen of the vendor, get ready to buy a physical 'hardware wallet' in CC format with NFC.
Same mechanism, just without trusting a bank which will again take fees from the vendor..
Before answering me you totally ignored my below first line of comment.
"I think this is practically not going to happen in near future, at least not before the lightning network become fully functional for masses."
I am not following LN now but I think they are nowhere near to their mainnet release.
Only future will tell how this CC concept will go , but if in 1990 that you tell some body that if you pay with CC, you will get time of (max 51 days to 30 days) to pay full and in top of it you will 2-5 % cashback then guy will totally think you as insane or scammer at that time,
Who knows, if you give me 1% cashback in bitcoin and fraud protection then why should I bother to keep my mobile and hardware wallet.
(This will defeat the purpose of peer to peer currency but things changes with time)