We can understand the necessity of the GSTN as discussed under the vision, mission and values statement given in https://www.gstn.org/vision-mission-and-values/
Vision
To become a trusted National Information Utility (NIU) which provides reliable, efficient and robust IT Backbone for the smooth functioning of the Goods & Services Tax regimen enabling economic agents to leverage the entire nation as One Market with minimal Indirect Tax compliance cost.
Mission
Provide common and shared IT infrastructure and services to the Central and State Governments, Tax Payers and other stakeholders for implementation of the Goods & Services Tax (GST).
Provide common Registration, Return and Payment services to the Tax payers. Partner with other agencies for creating an efficient and user-friendly GST Eco-system.
Encourage and collaborate with GST Suvidha Providers (GSPs) to roll out GST Applications for providing simplified services to the stakeholders.
Carry out research, study best practises and provide Training and Consultancy to the Tax authorities and other stakeholders.
Provide efficient Backend Services to the Tax Departments of the Central and State Governments on request.
Develop Tax Payer Profiling Utility (TPU) for Central and State Tax Administration.
Assist Tax authorities in improving Tax compliance and transparency of Tax Administration system.
Deliver any other services of relevance to the Central and State Governments and other stakeholders on request.
Values