For many games, PBP compression matches or beats CHD. For example:

Included with "Keys.bin" files where necessary for older PSP firmware. How to Use PBP Files

Many community members share "Starter Sets" or "Best of" collections that have already been converted to .PBP for plug-and-play convenience on handhelds like Anbernic or Retroid devices. How to Convert Your Own Games to PBP

: Use these archives as resources for learning game development, especially for those interested in PS1 game design or creating homebrew for the PSP.