VH1 didn’t publicize the show’s cancellation in 2006, but it’s possible that the network had moved on from the original series as it built out a few reality TV brands.

The Surreal Life was one of VH1’s first reality shows, but it spawned more than a half-dozen spinoffs. VH1’s Flavor of Love and Rock of Love with Bret Michaels both owe their success to The Surreal Life, as they were spun off from the first Surreal Life spinoff entitled Strange Love. VH1 also aired The Surreal Life: Fame Games in 2007.

As the network developed more celebreality series, The Surreal Life had likely run its course.

Source: https://www.distractify.com/p/why-did-the-surreal-life-end