Unless you own an original copy of the game (DVD or Steam). Downloading a "highly compressed" cracked version of GTA San Andreas from a random website is copyright infringement. Rockstar Games owns the IP, and the official "GTA San Andreas – The Definitive Edition" is available for purchase on Steam and Rockstar Launcher.
“There is no way it can compress by that much given how much information we know is in the game.” Quora · 9 years ago Gta San Andreas Highly Compressed 700mb Pc -
Downloading or distributing pirated copies of games violates copyright law in many countries. Even if a compressed package is technically easy to share, using legitimate copies supports developers and avoids legal and security risks. Unless you own an original copy of the game (DVD or Steam)