Many will be surprised by this move from Kraken to Coinbase. Here are a few benefits and reasons:
Coinbase volume is now nearly double Kraken as it has been dropping for months. This makes them the largest crypto exchange out of the USA
Fewer crypto shows less choppiness than Kraken
Less correlated coins to BTC
They are trying to comply with the US regulators to kiss their butts which means over 50% of the my entire global base can be supported for crypto
They are trying real hard to become the goto exchange for institutional capital.
They will most likely become the place to transact with crypto as they are trying to become the default login for websites and apps.
Just like Binance, they have way more development newsworthy stuff as compared to slow moving Kraken.
http://quantlabs.net/blog/2019/08/why-i-switched-from-kraken-to-coinbase-cryptocurrency-exchange/