Given the risks, you must weigh the benefits against the potential consequences. Based on the information gathered, here is a realistic analysis:
Shady download sites frequently disguise trojans, ransomware, and miners as compressed game archives. Because the files are heavily encrypted or packed with custom tools, your antivirus might struggle to scan them properly before extraction.
Many 300MB builds include "SkyGFX" or texture patches that make the game look better than the 2004 original, even with the compression.
The "300MB Highly Compressed Extra Quality" version of GTA San Andreas