Dolphin, the premier Wii/GameCube emulator, reads .wbfs files directly. While Dolphin can also use .iso or .rvz, the WBFS format is a middle-ground:
On various forums (GBAtemp, Reddit’s r/Roms), you will find references to "Archivists" who maintain complete WBFS sets. These are often distributed via Torrent or Usenet. wii wbfs archive
The most famous reference is "The Wii WBFS Archive" – a collection that aimed to bundle every game, update, and DLC into a single torrent spine. Wii WBFS Archive Guide Step 1: Hardware Requirements
Nintendo actively pursues legal action against ROM distribution sites. WBFS archives circumvent disc-based copy protection, which may violate laws like the Digital Millennium Copyright Act (DMCA) Section 1201. USB Hard Drive: 2TB capacity (Maximum for Wii USB Loaders)