It all started when my on ramp coinsquare gave up all there client list and wallet addresses for high profile investors. Much of my crypto assets were being traded on HitBTC who had my KYC info because I was leverage trading which is illegal in Canada. To stay legal I had to transfer my assets to Coinbase to avoid paying income tax of those funds as long as I held them in bitcoin or eth otherwise a tax event occurs. Coinbase sends me a monthly statement of my holdings and forwards that same info to CRA so they know I'm not practicing tax evasion.  I leave my Coinbase account going as a way to appease the government, but trust me I  handle my other stuff completely different now.