Like most sites of its kind, PSP ISO Club eventually began to fade. Domain renewals lapsed. Hosting costs rose. By late 2022, the main URL started redirecting to parked pages. Some mirrors exist on the Internet Archive, and fragments of the community moved to Discord or Reddit (/r/PSP remains strong).
: Compressed ISOs used to save storage space on memory cards. psp iso club 2021
If you own a physical PSP and a UMD drive (or a specific old model PS3), you can use homebrew software like "UMDumper" to create your own 1:1 ISO files. This is 100% legal. Like most sites of its kind, PSP ISO