But as long as you can have a trusted central authority, you don't need blockchain without needing to trust all the clients. The central authority can enforce authentication and authorization for what each client can do, combine with proper logging it is already sufficient. Blockchain is only needed if there's absolutely no central authority (which is not the case for any traditional business as by nature they already have a hierarchy where the top would act as the central authority, therefore any business that implements blockchain internally is just BS-ing).