There has been a recent news article about the FM claiming that they were able to access encrypted messages and emails to determine crypto related transactions and eventually led to the seizure of a large volume of money.
If you look at from the Ministerial side of things, keeping their habit of sucking money from the middle class side, money laundering is what is the biggest reason why they are not allowing crypto to become legal.
Even then, I would suggest people to avoid using Instant messenger apps to deal with crypto, you never know when you end up getting flagged as a false positive, but I could be overthinking - maybe they monitor accounts with excessive volumes before flagging them.
A lot of questions regarding who can view encrypted messages and so on come in but lets keep that aside for now.
You can read about the article here
FM Claims Access to WhatsApp Messages Led to Seizure of Crypto Worth Rs. 90 Crore