You couldn't be more right


The storage space is the means, not the end. Transactions per second is what's actually important.


Storage space is not the only means to increase the transaction rate. It may be the most effective force multiplier, but it's equally effective at persuading users to not run a Bitcoin full node. And the network of Bitcoin full nodes is what makes everyone's BTC valuable, so we depend on getting the balance between transaction space and a decentralised Bitcoin network exactly right. This means the blocksize has to be as close as possible to exactly the right size to reflect that balancing act.