URLs are surprisingly temporary things. Domains change, websites get reorganized, projects get renamed, and /final-v2-really-final/ eventually stops being final.
A rslvr.link address stays put while what happens behind it is free to evolve. Redirect somewhere, show information, group resources, control access, or create an experience with its own rules and lifecycle.
It’s useful for QR codes, printed material, documentation, games, physical spaces, temporary experiences, and anything else where changing what happens behind a link shouldn’t require changing the link itself.