One of the first people I've seen suggest that planned obsolescence is a good thing for consumers. Let me guess, you are somehow financially motivated to see people buying more stuff more frequently?
Cheap goods make things more accessible to more people. Planned (or even unplanned) obsolescence is an unfortunate side effect.
Re: planned vs. unplanned: I don't think the cheap fan manufacturer really builds it that way so you keep having to come back when yours breaks. At least, I don't think that's the primary motivator. More likely, their goal is just to sell more units in the first place, and lower prices are usually a good way to do that.
(Meanwhile, companies like Apple have found the holy grail: an expensive, high-margin, premium product that's difficult to repair.)
If you did spend $150 on a fan today, it would probably last just as long as a $15 one. Emphasis on probably, there are good quality items... just not a lot.
TVs are a great example: a $900 Sony smart TV I got 5ish years ago lasted barely longer than its 3 year warranty (before a hardware-related bootloop). A crappier cheaper TV would have lasted the same.
Seems to be the trend when introducing smarter software features. Near every appliance I had to replace in the last decade died because of "the motherboard" (according to several technicians), which was coincidentally about 50% the price of the appliance. I guess manufacturers like to cheap out on embedded hardware components?
> Near every appliance I had to replace in the last decade died because of "the motherboard"
Part of this is because appliance repair techs are not skilled in component level repair. They are trained to understand module-level repair, and that's it. It is possible to do more precise repairs, but mass manufacturing makes new modules cheaper than skilled (western) labor.