Isn't that a benefit of the blockchain? Since its inception in 2008, Bitcoin's database has never been hacked. They don't need to spend money on security, because mathematics is the security. The chain's integrity is powered by decentralized nodes and proof of work. At scale, while Proof of Work is increasing in cost, it is still probably cheaper and more secure than the aggregate cost of securing money at banks, servers, overhead, etc. And there are opportunities to make it cheaper through concepts like Proof of Stake.