>and that if or when something inside it goes wrong or needs servicing, it should be easy to do so.

Be careful and precise please. What to you mean by "easy" here in the context of the general public? I think what most people mean by "easy" is "I drop it off/send it away, and I get back something working within a day to a week depending on the product and faster is better, and it costs me nothing for [reasonable amount, minimum 2 years then 1 year per $300 up to 5 years] and then is reasonable for the remaining expected product lifespan" and how that happens matter not one whit. Case in point:

>Batteries are a wear item for example, and should be easy to swap out with spares available freely.

I strongly disagree with you on multiple levels here. I want my mobile device optimized for the general use case, which is when I have it on me by itself and it is working. That means the highest active matter ratio possible while also being as passively environmentally resistant as possible and it being functional for a few years at a time. Exceptional scenarios can be handled with cases. It's always possible to add extra matter for protection or battery, but obviously the base phone defines the minimums. Beyond that I'm perfectly happy to bring it to a service center for an hour dealing with the battery every 2-3 years. "Easy to swap out" is a negative here because it lowers the active matter ratio and effectiveness of the device in the most common scenario in favor of a niche concern [1]. And while I expect batteries to last for their rated lifespan and that to be what most would expect under normal usage (couple of years), I do not expect them to be "available freely" beyond that, they're a complex and critical core component that can expected to be a not-insignificant percentage of device BOM.

>Screens and glass backs are prone to cracking and shattering

No they aren't. They're very resistant to cracking and shattering, but a small percentage of people are prone to dropping them or need to use them in extreme environments. Those people should take advantage of the wide variety of 3rd party products optimized specifically for their individualized use case.

>I'd be happy to see some kind of legislation put easy access to spare parts as a priority.

I have strongly (to the extent I am able) fought such legislation, I think it's awful and wrong headed. What I would very much support is legislation along the lines I've discussed, requiring manufacturers to Deal With non-functional devices of customers for a good 2-5 years are no extra cost beyond perhaps extreme shipping, and requiring them to then 'ensure service is available' at cost of time&parts for some period afterwards. I expect different companies targeting different use cases and different segments of the population would adopt different methods to meet this. Some of them would definitely focus heavily on ease of repairability, particularly at the low end. Others would lean more heavily on engineering/production, QC, and "insurance" (replacement margin built-in to price). Either is fine, it's not a moral question just one of results.

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1: One which I question anyway, it exclusively applies to someone who needs more then internal battery life and requires specifically the extremely narrow band of a somewhat heavier phone or worse battery life phone but not quite as much as a minimal battery case would be and must use it constantly for hours with only seconds of downtime running around (or else it'd be better to just plug it in to a larger battery for a little bit while grabbing a snack or it's steady or whatever). Frankly I struggle to figure out who exactly this applies to for mobile devices.