Unlike SD cards, film has an expiration date. Once it reaches the end of its shelf life, all sorts of unpredictable things can happen: loss of sensitivity, decreased contrast, color shifts, fog, etc. Some people see that as unacceptable, some see it as artistic charm. Here's how one roll held up after over three decades of languishing in a bag.
This great video from This Does Not Compute is a nostalgic look at the process of shooting film in addition to a peek at how well a decades-old roll of Plus-X pan held up in shooting. In fairness, the film is low sensitivity and black and white, both of which help it to weather the years a bit more, but it's still interesting to see the results. The final shots are a bit flat and definitely grainier than typical ISO 125 film, but I personally thought they were perfectly usable (particularly with a quick contrast adjustment) and rather charming. And at almost $1.50 a shot, it's interesting to hear him talk about it rewired his process. Despite the drawbacks, I still enjoy the thrill of opening prints for the first time; that's something that just can't be replicated by importing raw files onto my computer.