Enterprises are using blockchains based on trust rather than proof of work. The trust is often manifested as some level of consensus among nodes and the tendency of a node to offer a 'dissenting' value is a basis for establishing the degree of trust. For example 70% of trusted nodes concurring. In some protocols each institution can maintain its own list of trusted nodes. In other protocols the list of trusted nodes is agreed among institutions. Like all engineering, it depends.
They use blockchains because it is a fast way of conducting transactions relative to existing infrastructure that is architected based on incremental automation of manual processes. Transactions on a distributed ledger can clear quickly relative to standard send->ack->transmit->verify protocols with human scale execution times.
Is it all rosey and perfect? No. There are bugs in the system. There are bugs in every system including the existing system.
They use blockchains because it is a fast way of conducting transactions relative to existing infrastructure that is architected based on incremental automation of manual processes. Transactions on a distributed ledger can clear quickly relative to standard send->ack->transmit->verify protocols with human scale execution times.
Is it all rosey and perfect? No. There are bugs in the system. There are bugs in every system including the existing system.