In February 2022, Google introduced a new, integrated view for Gmail, making it easy to move among applications like Gmail, Chat, Spaces, and Meet in one unified location.
Beginning this month, April 2022, anyone who has not already opted-in to the new experience will begin seeing the new experience by default but you will still have the option to revert to classic in your settings until July 2022 when this new experience becomes standard.
Learn more about the new GMail view experience and the timeframe for its rollout.