When something on my car breaks, I take it to a person that has no direct affiliation with the company that built my car, and it is always cheaper than taking it to the local repair shop that the manufacturer runs. Always.
I can also replace the parts in it with parts manufactured by yet another third party. Again, the parts of equivalent quality are nearly always cheaper than the original manufacturer's replacement parts. You can also spend more on premium aftermarket parts, if you like.
I don't even want to change the oil in my car. But I can pay someone who wants to service and repair cars all day, as their job, to do it for me, rather than sending the car back to the factory to have its engine replaced every time the oil gets dirty.
If I like tinkering with electronics, I could swap my own iPhone battery, and then I could also do that for other people. The problem is that Apple, Samsung, et al do not wish to share the repairs market, or allow repairs to eat into new sales, and therefore do not sell repair parts at reasonable prices or release part specifications so that third parties may produce repair parts of equivalent quality.
So the only way to get cheaper than an official first-party repair is to get crappy grey-market parts. Proprietary and patented connectors that don't get licensed on reasonable terms make things worse. This stuff doesn't need to be repaired by everyone, but it needs to be repairable by someone that isn't beholden to the original manufacturer. Repairability is the consumer check on planned obsolescence.
Apple is notoriously draconian about ensuring that 3rd parties are blocked from accessing schematics and repair manuals. I'm talking, they threaten lawsuits to anyone publishing schematics, and there is no legal way to obtain those schematics unless you're an Apple authorized repairer - in which case you'll never need them because your job is just to replace entire logic boards after minimal diagnostics. This creates enormous waste and costs a lot more than an actual repair would. In some cases they don't even do that and just tell the user tough shit, get a new device.
Clearly you have not been to Asia. Plenty of 3rd party iPhone repair shops. Very easy to get batteries and cracked screens replaced.
I think people have been successfully conditioned to view phones as disposable/replaceable. It would take an almost Sisyphean marketing and conditioning effort to change that thinking.
I'm not sure it's possible. But, hey, I suppose Apple's free to try. No harm there I suppose.
Outside many European Apple stores they even often pay someone to stand and hold a sign advertising cheaper iPhone repairs available around the corner etc.
Anecdotally, a large number of my friends and family have all used these, usually for cracked screens or batteries, and often in preference to an Apple store on the (sometimes incorrect) assumption it will be cheaper than “taking it to Apple” to get fixed.
The reason they're everwhere is that people do take their phones in for repair. Mostly battery replacement and cracked screens. The town I live in manages to support three repair shops that I know of.
The first thing you do when you take them out of the box is to put the battery in.
Even if the person at the store does this for you, just by watching you can easly do it yourself.
And since iphones are a huge role model, if they implement it others will follow along.
Shocking, I know...
If Apple wants to make resilient devices they'd start by using materials not as fragile as glass or thin aluminium. Say, differentially hardened steel (incl. plated) or advanced composites. Just like watches.
Then, the only problem is extra space for the battery connector. They could even sell users a prismatic pouch with no plastic shell as the battery.
The actual tricky part is that integrated battery allows better cooling by use of messy thermal compound. You could have a foam thermal pad instead below the battery cover.
We used to be able to buy Fisher-Price toys that were tough enough to bear the weight of a car, or withstand multiple generations of abuse by children. I've got plastic toolboxes inherited from my grandfather that still hold up.
Take a look at the ratings and user photos for plastic vehicle ramps on Amazon and consider whether you think you could even get the jack stands in before the ramps collapse. Kids' toys are flimsier than ever, yet despite the "cheaper" construction they're also more expensive than ever. I bought my kids the Barbie Dreamhouse (a $100+ marvel of plastic and cardboard) that collapsed under its own weight. The original Nintendo equipment was light-years more rugged than the endless RMA experience that is the Switch.
We have the technology to make plastics that don't feel "cheap" and the products reusable, but for whatever reasons we've clearly steered away from these goals.
But here’s another tradeoff: if one is producing phones for the great portion of the market which needs or wants disposable devices, then one doesn’t get to claim that one is designing durable devices.
What are the tradeoffs for a user replaceable battery? (really, this is something we should all know if we are arguing FOR replaceable batteries - maybe it's not the best idea?
I would wager 99%+ of sales go to people who never want to touch the innards of a phone.
And anecdotally, my SO's father got a cheap battery for his iphone and it ballooned up and almost destroyed his phone.
He also asked me if he should get a 3rd party power adaptor for his macbook (I said no, he ignored me because his wife is cheap), and it was this cheap POS that actually ended up forcing him to doa $600 repair AND get an apple power supply.
I spent years working on consumer PCs - normal people dont have time or inclination to deal with all this crap, just like they don't want to learn to repair their own air conditioner.
Consumers who want/need easily replaceable batteries already don't choose an iPhone, so all this in mind, I suspect the numbers don't add up for this argument.