Bitcoin will grow layers above the base layer -- the blockchain -- that will enable instant transactions, microtransactions, and other scalable issues.
Do not think that the blockchain is the only way to transfer bitcoins.
Larger aggregators will easily compensate for current maximum block size in a scalable manner.
All nation-state/fiat currencies are multi-layer. Too many people look at what bitcoin does now, and assume that those are the only currency services that will ever exist.
These other layers may indeed assume that role someday, but it should happen because they prove to be superior on their own merits, not because the capabilities of blockchain transfers are deliberately crippled.