Because TeknoParrot requires the actual game files (extracted from arcade hard drives or USB security dongles), these files are large (often 8GB to 40GB per game). Hosting these on standard file-sharing sites leads to constant takedowns. Archive.org has a legal exemption for preservation, allowing many "abandonware" collections to stay online for years.
Furthermore, the industry utilized heavy security measures. Games were often tied to specific serial numbers, hardware dongles, or "key chips." If you simply copied the files from the drive to a PC, the game wouldn't run. It would detect the wrong environment and crash. This made the games difficult to preserve and even harder to play legitimately. teknoparrot archive.org