I am less familiar with their shower accessories than their trashcans. Historically, Simplehuman puts a ton of thought into their designs and materials.
Unfortunately, rust-proofing something that is exposed to water every day can be difficult. While reviews for the Simplehuman caddy are mostly positive, the negative reviews are overwhelmingly about it rusting. It may vary by how hard the water is in your place.
They look cheap, but a plastic caddy won’t rust. If that’s you major concern, perhaps that would be worth considering?