Loading games from a hard drive via loaders like USB Loader GX or WiiFlow is often faster than reading from the original, slow optical drive. Acquiring and Using ROMs
Downloading Wii games from the internet without owning the original disc is copyright infringement (piracy). While the Wii is a "legacy" console and Nintendo no longer manufactures the hardware or sells most of these games new, the copyright is still actively enforced by Nintendo. The company has a history of issuing DMCA takedowns to sites hosting their ROMs.
The Ultimate Guide to Wii WBFS ROMs: Faster, Smaller, Better