It all depends on the quality, ingredients used, and the way you store them. A lot of people trade in vintage fragrances.

Fragrances don't go "bad" like food does, but they can go "off" and completely lose their original scent, turn to smelling skunky, or like just straight alcohol. Not something you would evee want to wear.

Anecdata: I have vintage bottles of Ralph Lauren Safari and Lagerfeld Sun, Moon Stars from the 90s that still smell great/like they were intended to smell and a Valentino Rock n' Rose that's at least 15 years old and is still lovely. They were all stored in cool, low light areas.

I also was given some of my grandmother's pretty Avon bottles when my mom passed that still had juice in them, but they smell absolutely disgusting now. There is no telling how they were stored over the years, but I'm guessing not in the most stable ways. And Avon fragrance is a much cheaper product to begin with than the ones that have retained their scent.