What actually makes outdoor furniture last?

Some people have the same set for 15+ years. Others are replacing stuff after two summers. Same weather, same basic care. What's the actual difference?

I keep going back and forth on frame material. Teak, aluminum, powder-coated steel, they all say "weather resistant" on the box but clearly don't age the same. Is the material the main thing or does it come down to how the joints are built?

Fabric is the other one. Solution-dyed acrylic vs surface-treated, does that gap actually show up after a few seasons of real sun or is it mostly marketing?

What's held up for you and why do you think it did?