The adaptive blocksize combined with the tail emission is what will make the Monero business model still relevant should the real cost of "keeping the ledger" fall by several orders of magnitude due to changes in hardware, networking etc. In this scenario Bitcoin could very well end up being Dinrer's Club while Monero could be VISA. Instead of simply dismissing fiat banking and credit / debit / payment cards it is important to learn their lessons of history. Those who ignore history are bound to repeat it.
Hm well lets do a little math. For the sake of simplicity lets say monero transactions are the same size as bitcoin transactions. And that bitcoins 1mb blocks are what are necissary to keep sifficient decentralization at this time. Lets scale it at moores law over 20 years. In 20 years that is 13 doublings. Lets say half the people on earth use monero for day to day transactions. Lets say the average person makes about 5 transactions per day.
We would need (3.5billion*5/86400) ~200,000 transactions per second. Bitcoin does about 7tx/s. 13 doublings would put it at ~60,000tx/s. I mean it's in the same realm. Throw 2 more doublings in there and you would be > 200,000. IF moors law holds. Sooo maybe. Maybe it scales well enough in 20 years without some scaling breakthrough.