Google updated the Gmail app with the Material You design last year, following the release of Android 12. The update allowed the bottom bar to become considerably smaller compared to previous iterations of the app, but now, with the latest server side update, the bottom bar has gotten significantly smaller. Also, the most recent Gmail update, as reported by 9To5Google, eliminates the icon labels from the bottom bar on Android.
The Gmail app formerly contained labels for Mail, Chat, Spaces, and Meet in the bottom bar beneath their corresponding icons, but Google has now decided to remove the icons in favour of more space, but upon checking, we found out that the new version displays the same number of emails as the version prior to the new version, essentially making the update tuned for aesthetics rather than functionality. Now, Google might improve upon the update and allow for more emails and hence, a more information-rich screen in the future.
The update is said to be a server side implementation from Google once users update to the 2022.08.07.x version of the Gmail client on Android smartphones. The update will be rolled-out to users gradually in different regions across the world.