It's doubtful that
anyone will be able to hold the entire blockchain at some point in the future, should Bitcoin become a mainstream thing.
Here's some interesting data (from 2006 only for the US)
Average daily number of transactions:
- 60 Million credit card transactions
- 100 Million Interbank ATM transactions
- 60 Million ACH transactions
- 15 Million SWIFT transactions
- 365.000 CHIPS transactions
- 521.000 FEDwire transactions
- 700.000 CLS transactions
So that's a cool 237 Million daily transactions, in the US alone,
excluding cash transactions.
Let's assume a conservative average of 3 daily cash transactions per person (buying the paper, a hotdog and a pack of smokes). That adds a cool 1000 Million transactions for the US alone right there.
Yeah. Better go grab a YottaByte HD real quick.
I think it is agreed that most Bitcoin payments won't take place on the blockchain. e.g., with tx replacement you can have one transaction carry multiple payments, and there can be various 3rd party services (I'm using "various" in a mostly positive sense - Bitcoin enables possibilities with good tradeoffs, better than the current banking system) . So 1B daily payments doesn't mean 1B daily transactions. The more transactions can actually make it to the blockchain, the lesser the overall "tax" (in the broadest sense) of using additional layers.