So, if i userstand correctly if you download game(apk) from google play, it doesn’t download straightforward apk-file, it downloads archived apk-file(more or less how webgame platforms do)
archived apk-file becomes 1.97mb
bundled to aab-file it becomes 1.9mb (without archiving, in fact archiving doesn’t reduces size)
Yes, for the end user, it’s similar to web and gzip compression. The store compress it’s using the best compression for the end user device/OS, and it’s uncompressed during/after downloading.
An AAB is a container that Google Play uses to generate APKs based on the AAB configuration and the end user’s device or OS. For instance, if you include both armv7 and arm64 in your AAB, Google Play creates separate APKs and delivers the one that best matches the user’s device architecture. Branching can also be done by other factors, such as supported texture formats, languages, and more.
Even if you upload an APK, Google Play preprocess it and may apply changes to AndroidManifest or/and something else.