How scalable is a Blockchain-based system?
Blockchains are not really scalable. For the most security, blockchains need to be replicated on as many devices as possible. Those devices are full nodes and must download and verify every single block and transaction. In order to increase the number of transactions, transactions have to become smaller and blocks have to become bigger. Unfortunately increasing block size and transaction capacity will result in more resources required to verify and store them all.