Everyone will be using the Bitcoin blockchain to run their banking infrastructures, because it doesn't make sense to use any other blockchain. Not using the Bitcoin blockchain = guaranteeing your shit will get hacked. For some reason they STILL keep the "blockchain tech" thing but tend to avoid the part where a cryptocurrency is basically the fuel that keeps the blockchain running.
If everyone uses bitcoin blockchain, your home computer will not be able to cope with the size.
Some mutuals (building society) can pass on the savings.
You shouldn't be storing the blockchain on your home computer anyway.