tl;dr: Tim Berners-Lee argues that URIs break not for technical reasons but because of poor design choices—embedding things like file extensions, CGI paths, authors, topics, or status in URLs guarantees they'll change when your organization, tools, or classifications inevitably do. The fix is to design URIs with minimal information (a creation date plus an opaque identifier works well) and use server-side mapping to decouple URLs from filesystem layout. Broken links damage user trust and are almost always the webmaster's fault, not an unavoidable consequence of the web.