I'm afraid since the Health & Safety movement killed this idea a decade ago.
Once a court found that a disclaimer like, "Live parts inside, no user serviceable components inside. DO NOT OPEN" was not enough to prevent getting sued when a user opened it and hurt themselves... they started making things unservicable, unopenable, undocumented and removed all hint or ability to repair it yourself, so when someone hurts themselves the company can get away saying there was not even a whiff of suggestion that a user should open it.
In the UK we used to buy white goods without a plug and it was the users job to wire the plug after sale. This changed to all products having to be fitted with moulded plugs which cannot be opened. Just an example. There are more.
It's also cheaper to glue, heat stake, rivet or spot weld things together to produce cheaper goods.
It's come down to recycling getting cheaper with cheaper labour than repairing things.
Consider cars though. They are repairable, almost indefinitely if you can avoid rust. However, take my car for example. If there is a failure involving several components, they have to be replaced as a set. A principle example would be if you lose a key. The insurance will not insure it while a valid key is out in the wild. A new key (OEM) is £350. However, the key code is burnt into the ECU in ROM at manufacturing time, they claim for security. So, in order to reinsure the car you need 2 new keys, the door locks replaced and a new ECU. Total cost at a dealership, £2500-3500. Most lost key insurance is £1500 or less.