Article is a load of crap
First of all, no tablets are "welded together". You don't need to bin them if the battery goes dead, but unless you're pretty handy you'll need to have it serviced to have that done. What percentage of people do you reckon replace their car's tires themselves, versus going to a shop and having it done? Every car comes with the equipment necessary to change your own tires, so why do so few do it themselves?
The reason why you have non user serviceable parts like the batteries in tablets, or can't replace a tiny part in your TV like you used to but have to replace the entire control board is not because of a vast conspiracy to force people to throw away stuff that is 99% working. It is because it is cheaper to make them that way, and this integration and design with "no user serviceable parts within" makes the product more reliable!
You know why TV repairmen are a thing of the past? Because fifty years ago TVs broke down WAY more frequently than modern TVs do, and they were VASTLY more expensive. Go look at some ads for TVs in 1950s and 1960s, and compare those prices with the typical incomes of the day. Even a 70-80" TV is much cheaper now in real terms than a 20" color TV was in the 60s! When your TV effectively cost $5K or more and broke down on at least a yearly basis, of course you're going to fix it! Tossing it out would be like buying a used car for $5K and tossing it out when the brake pads wear out.
The trend toward greater component integration has driven down costs, which isn't just in the manufacturer's interest, it is in the consumer's interest. Most people will not pay more for something based on a higher expected reliability, and almost no one will pay more for something based on it being user serviceable. People would rather have something for less now, and if worried they might fail too soon will purchase the extended warranties that most retailers offer.
Fifty years ago it was common for car owners to change the oil themselves. It is quite uncommon now (at least in the US, I can't speak for the UK/EU) It isn't because it has become more difficult, the process is pretty much the same for modern cars as those from the 1950s and 1960s. One might try to argue that it is because they don't have to, as automakers have recently started including basic maintenance such as oil changes during the warranty term - but that ignores the fact that people no longer changing their own oil PRECEDED that change, so it could not have been caused by it.
Why should companies put a premium on user repairability, or any repairability, if consumers do not put a premium on it, as evidenced by the fact that most are not willing to pay more to get it, and often don't take advantage of it even where they still have it?