I have found some perfumes go off and smell horrid in old age but others seem to keep well as long as they are kept dark and cool.
My oldest bottle is about 25 years old and still smells exactly the same. It’s Penhaligons Violetta. Still love it and I bought a supply just before it was discontinued so I should have some for years to come.
Some of my older Jo Malone’s have kept well - Pomegranate Noir and Vetiver- but Red Red Roses went very yucky after about 5 years. All were kept in their boxes.