The primary selling point is the size. At roughly 100MB to 150MB, this is a lifesaver for gamers with slow internet connections or strict data limits. It downloads in minutes rather than hours.
Searching for a "highly compressed" 100MB version of Grand Theft Auto: Vice City for PC can be risky. While the original 2002 version was relatively small by modern standards, it still required significantly more space than 100MB. The Reality of "Highly Compressed" 100MB Versions
These files are frequently used as "bait" for trojans, adware, and other malicious software.