The APK file format doesn't actually have a strict file size cap. There are rules for sizes on Google Play and some of the package extension types through Play Asset Delivery have limits (4GB for most, up to 34GB otherwise, and unlimited if they use a private CDN for delivery), but the 2GB figure you see on Itch is arbitrary and placed by them. Large APK files are more a problem because they can become unstable during the install itself (has nothing to do with them running after), but realistically, there are games here that link externally to their Android downloads, and they install just fine despite being larger than this one.