all plastics and aluminium decays after about 10 years. if it's load bearing it's garbage after a decade.

the best things are made of steel or copper.

you really can't fix aluminium bicycle frames, they are eventually going to fracture once they get to a certain age, the corrosion process eventually opens cracks all the way through. steel bicycle frames even when they do get bent or snapped can be repaired and be safe again.

plastic bathtubs also eventually crack and get nasty. rubber rarely lasts even 10 years, silicone is not much better, and gets hard rather than sloppy. polyurethane lasts a lot longer but eventually it tears and crumbles. magnets eventually demagnetise.

these materials will eventually be phased out again because they are toxic and inefficient in the long run.