The claim
Consolidating duplicates onto a single canonical URL concentrates signals and avoids diluted, competing pages.
What the evidence shows
Google's guidance on consolidating duplicate URLs explains that when it finds duplicate or very similar pages it picks one canonical to index, and that publishers can influence this choice with signals such as rel=canonical, redirects and consistent internal linking. Splitting the same content across many URLs dilutes ranking signals. Declaring a clear canonical concentrates them.