Since repacks are distributed through unofficial channels, there is a risk of malware or "cryptojackers" being bundled with the installer. It is critical to only use trusted sources like FitGirl or DODI .
Repacks are technically a form of software piracy if they distribute copyrighted game files without permission. While some users "buy the game but download the repack" to save bandwidth, the distribution and use of these files often violate EULAs and copyright laws. Steam-Repacks
Because the files are so tightly packed, the installation process requires significant CPU power and time to decompress and extract the files to their original state. Steam-Repacks