If you used Inbox, it also categorizes flights, hotels, calendar entries, restaurant reservations, bills, newsletters, forums, social media updates, and a host

If you used Inbox, it also categorizes flights, hotels, calendar entries, restaurant reservations, bills, newsletters, forums, social media updates, and a host of other useful functions, extracting out entities. The Finances, Purchases, and Trips bundles are extremely useful. This information isn't solely surfaceable in Inbox or Gmail UI, go to any Google Search box and type "my purchases" or "my flights" or "my reservations".