I always feel like half a story is told when I hear about the planned obsolescence and how manufacturers are screwing us all. It always start with an example of device breaking apart right after warranty expires and ends with "it was better in the old times". Is it really that black and white in the world of electronics?
If you compare "good old times" with now, you will see that electronic devices are dirt cheap. Big part of that is economy of scale and cheaper hardware chips. But it is also due to newer, smaller processes enabling manufacturers to fit more chips into the same wafer area which enables them to earn more. And yes, with all chip competition out there, more often than not these savings are passed to consumer.
But smaller process also impacts durability - chip with a foot-wide oxide layer (exaggerating a bit) is definitely going to have more durability than something done in 10 nm process. So yes, that newer, smaller, more power efficient, and undoubtedly better chip will fail sooner than one used in the phones of old. There is no escaping laws of physics.
Another complain I often hear is that nothing can be fixed these days - if something fails you must buy new. And that is bullshit too - almost everything can be fixed. Search on YouTube and you'll find people playing with BGA level repairs all the times. Real issue is that, while everything can be fixed, it is often not worthy to do so - unless you do it yourself.
Think of the guy doing diagnostics for something as simple as dead capacitor. If he is lucky he can find it fast, if not he might spend hours troubleshooting board that costs $200 to repair. Even if final repair is just a $1, he needs to charge his time. Quite often math ends up being that cost of troubleshooting is simply too high compared to the cost of buying new. It is not that stuff cannot be repaired. It is just that's not worth the time.
And that is without taking into account time one needs to open the damn device. If we use a phone as example, often you will find excessive amounts of glue without a screw in sight. But that is not (only) manufacturer's problem. People want nice, curvy designs. People don't care about the screws when they are buying the phone. I can bet you that 9 out of 10 people will just care that something looks beautiful and that it is cheap. Only time they will care about accessibility of inner hardware is when device fails.
What makes the new devices cheaper all the time is extensive use of plastic, avoiding screws to lower cost of assembly, and removing all parts you can live without. Any manufacturer that would build their devices purely for maintainability and durability would probably be bankrupt within a few years. Partially because its devices would be more expensive but partially just due to time needed to get design just right.
Do we have a problem with devices falling into the obsolescence faster and faster? I would say yes. But manufacturers are not to blame. It is us consumers voting with our wallets. As long as consumers want cheap and beautifully designed devices, repairability will suffer.