Pollution - policy paralysis and prejudice - doctored reports by Premier Organisations

Source Indian Express 15th December 2021
The study further says that between 2013 and 2020, Delhi hasn’t experienced a single year where the NO2 annual average was within safe limits. The study notes that Delhi has taken progressive measures in its policies, including introducing CNG autos, country’s largest and busiest Metro rail network, introducing BSVI fuel from 2018 and scrapping vehicles older than 15 years. Despite these measures, the city has been unable to keep its NO2 levels within permissible limits. Even during the lockdown in 2020 with little or no vehicular and industrial emissions, which are two major contributors to NO2, while NO2 levels were significantly reduced, it still exceeded the CPCB limit.
I am reproducing some of the paras of the letter addressed to Union Minister for Environment, Forests and Climate Change:-
8. Now after observing the ongoing proceedings, looking at the embargo imposed and consequently level of pollution existing in the Capital City and NCR, I am more than convinced that my studies related to pollution caused by Aviation, Indian Railways and National Highway Authority of India (NHAI) for over 12 years have proven to be correct, because the pollution caused by Aviation, Indian Railways and NHAI does not figure in any of the studies by IIT, NEERI, and CRRI just to help the polluters by design. This belief finds strength of “U Turn” by Central Govt on Pollution caused by “Stubble Burning”.
9. After reading the decision by the Air Quality Management Commission, in particular ban of entry of trucks in Capital City is nothing but a classical joke as most of the Trucks bound towards States other than Delhi now use Peripheral Express Way and do not enter Delhi.
Similarly, all over the country most of the Gas Distributors are using cycle rickshaws fitted with old scooter or motorcycles popularly called as “Juggads”, which once again do not exist on the records of Transport Department.
The moot question arises that why such alarming  report did not raise concerns in the past and why now only after questioning them?