Metal or plastic-coated steel trellis: which lasts longer outdoors?

Across the reviewers we read, plastic- or powder-coated steel is the consensus middle ground: it resists rust longer than bare steel and is sturdier than all-plastic stakes, which specialist gardening subreddits repeatedly call out as too flimsy for indeterminate tomatoes or heavy cucumbers. Bare metal can last longest if galvanized, but most sub-$50 Amazon trellises rely on coatings, so coating quality (and whether welds are sealed) is the failure point reviewers flag most often.