Storing data on blockchain is too expensive and inefficient as for upload and for the access. The only small chunks of data can be stored on blockchain and also in most cases they are immutable, i.e. you can’t delete or edit it. To make change you must generate the next block with that change. It’s not fast.
And also the size of the blockchain will include all world data, at the moment it’s greater than 460 Exabytes. And you would need to store it on the each node in the network, because blockchain is used a replication mechanism to achieve the reliability.
You can read about replication there:
The other problem is scaling - each block must be confirmed by consensus, in most today’s blockchains it requires coordination to have majority of the network to confirm the block. And with growing of the network this process demands more and more coordination. As result - it’s incredible slow from storage point of view.
Any blockchain-based storage solution is doomed at start because of those reasons.
At the moment only p2p networks can reach both - speed and reliability, but has less in common with the blockchain.
You can read more about consensus on Storj there: