Because this is labeled as it is part of a split archive. To use it correctly, you must follow these steps:
The software will automatically pull data from part2 and all subsequent parts to recreate the original full-sized folder. Because this is labeled as it is part of a split archive
You can find the official, full version of this pack (which includes all parts) on the ArtStation Marketplace . How to Handle Multi-Part RAR Files Because this is labeled as it is part of a split archive