I worked in the consumer electronics industry. It isn't about planned obsolescence, the idea never came up, instead it was about cutting every penny possible without incurring new expense from returns in the warranty time. The warranty time was all about the no income side of the product, the millions in cost from customers after the sale.
The thing consumers forget is that for things to keep running when they do need repair you need parts and someone has to stock those parts. Try to figure out the cost on making a product, then storing, maintaining and selling those parts for everything you make for years and years, nobody can stay in business unless you have very few products. Instead you estimate what most likely will fail and stock those for what amount time is economically feasible, usually the warranty period. The less likely a part is to fail the less of that part that is stored, things like the actual tv case, the frame of an appliance, etc.
If you buy a product you really like and want to keep it for years I suggest you buy the replacement parts before it breaks as they probably will not be sold when you need them.