Google makes Gmail Go available to all Android users2
Google released Gmail Go in the Play Store so that anyone can download and use it (via 9to5google). Gmail Go offers the same email experience as the full-fledged app, it's just that it does away with some visual elements.
For starters, it doesn't have the “Meet” button at the bottom of the screen. Also, the overall aspect of the app is slightly “cleaner” in the sense that it doesn't make use of shadows. Truth be told Gmail users can set up their app's UI so that the Meet button won't appear at all, but that's another discussion.
The bottom line is if you want to try out a lighter version of Gmail, supposedly optimized to work on devices with less RAM, you should be able to download Gmail Go via the Google Play Store right now.