As I understand it, the original academic paper introducing the concept of planned obsolescence, described it as an economic boon -- essentially a form of stimulus. At the time, the intent was not to sabotage the lifetime of products, but to keep introducing desirable new features.

Now, anecdotally, I think that I've witnessed planned obsolescence of a sort, in some kinds of products. I remember the home appliances in my house when I was a kid, being much more reliable than those sold today. I've had to repair literally every appliance in my house over the past decade, in some cases two or even three times. We're already on our second fridge. The cause may simply be due to relentlessly driving the cost out of those products while keeping an eye on the one-year warranty.