You'll soon be able to do a lot more in Gmail -- without ever leaving your inbox. Google will make AMP-powered "dynamic emails" for Gmail available to the general public on July 2nd, following a beta release to paying G Suite customers earlier this year. You've undoubtedly encountered AMP, or "accelerated mobile pages" if you've opened a link on your phone; it's a Google-built protocol that can load web pages using it a lot more quickly.
With AMP in Gmail, users perform web-based tasks right in their inbox, such as filling out forms, RSVPing to an event, responding to an edit in Google Docs, or browsing images in a carousel. The feature will only be available for Gmail on the web, with mobile due to come at an unspecified date.