In spite of planned obsolescence, there are still purchases out there that only get better with age. What are some of those?
Offhand, i can think of cast iron pots/griddles/skillets/dutch ovens. I don't think these ever wear out. And with good care, they have a wonderful patina, and they add healthful iron to your food.
Also, items made from good leather. Jackets, shoes, boots, purses, luggage, briefcases, carrier bags. By keeping leather in good condition and by actually USING them, the leather gets more supple and wears in beautifully. If you have a good leather item, find out where your local shoe repair person sets up shop, and become their favorite patron.
What else becomes better with use?