DOTEL/R/2018/80857

I want to know why for buying a sim or to open an account we used to give our personal and private information like finger print and all as we need to provide aadhar card to telecom operator or bank.
And if now this is not mandatory then how we will be assure that this information is deleted from their database if we are providing them other verification documents.
And who suggested to provide all personal and private details of an individual to private firms and to link everything with aadhar.