There are legitimate reasons users search for this file independently rather than letting the Play Store handle it:
Occasionally, Rockstar Games provides incentives, such as free copies, via their official launcher. Main.8.com.rockstargames.gtasa.obb File Download LINK
If you want to narrow down your troubleshooting, let me know: What your device runs The exact error message you see when the game crashes If you are using a modded version or the vanilla game Share public link There are legitimate reasons users search for this
The download speed fluctuated. 2MB/s... 5MB/s... The file was massive, a heavy anchor dragging the memory of a whole state across the bandwidth. Ensure you have enough storage space, as Android
Uninstall any previous versions or clones of GTA San Andreas from your device. Ensure you have enough storage space, as Android requires double the file size during the actual installation process. Safety and Legality Notice
This occurs during the APK installation stage before you even handle the OBB file.