To me this does not feel like planned obsolescence and feels more like a general case of "technology marches on".
The example here is stupid because the laptop is perfectly capable of executing a .? operator - there is no insufficient hardware or similar things. The only reason it can't is because of artificial limitations put up by Google, likely on the risk that some other, unrelated features might fail otherwise.
I don't think it's planned obsolescence in the sense that they specifically set out to brick the device - but they are certainly accepting that such devices becoming obsolete quickly in their planning.
You cannot predict all the possible future requirements of a product, the best you can do is make a reasonable effort. In this case the vendors likely could do some kind of patch/update to support .?, but surely there are a large number of other little things that have changed or been added over the years, not just .?. So, where does that slippery slope end? How many new features, and related regression testing should be put into older devices? Does the hardware vendor have a kind of ethical responsibility to continue to update it until it just absolutely cannot be carried along any longer?
In hardware designs there are always a lot of hard trade offs made to keep the bill of materials as low as reasonably possible. As new components become available new capabilities for the devices become possible, and at some point you need to focus your primary R&D efforts on the newer stuff just for efficiency sake.
My personal experience is that very few mainstream devices are really built with some kind of planned obsolescence. Instead, devices that become unsupported and unable to get current software updates are usually just victims of the basic drivers of modern business (profit, growth, etc.). Sure there are cases where the hardware vendor WANTS devices to expire early and force users to buy new ones, but when you look at the app store revenues of Apple or Google, I don't think they're sweating hardware revenue to the point they are implementing some form of planned obsolescence. They might even prefer that older devices were more cost effective to support in order to reduce the potential for churn to the alternate platform/ecosystem.
Li-ion battery arrangements inside those devices seem to hold about 80% of their usable capacity and voltage for about six months, with average usage patterns. A year after that this drops to 50% of original capacity, or below. This is known, if a bit too generalized.
Yet those are not easily swapped out. And your CPU throttles, your WiFi throttles down with the battery, reducing usability. There is no "please change out the battery" alert for the user at any point.
The marketing for these devices makes no mention like "you've got about a year of usage for this device before it becomes slow".
In any of this there aren't any external factors to anticipate, unlike with the Javascript landscape example above. As a manufacturer you know your device usage patterns, you do collect some telemetry and some repairs data. You can make a projection.
My point is, those are being sold in full knowledge of the facts of their limited lifetime. With no mitigation strategies, with no concessions for user-serviceable battery replacement or how to buy those batteries. There is no battery shelf at the Apple store.
It isn't discussed much. There is no customer blowback to this product strategy. It could be, in bad faith argued that people are fine with buying something to replace it a year later.
My question is, to you, are you arguing this in good faith? Do you really think this is fine to have something called a "product" where it is actually a service, with a limited term and no end-user serviceability?
Is it OK to call something a "question" where I am asking you to ask yourself, and don't care to hear what the answer is, because I have already arrived at an opinion long time ago and see no reason to change it hence?
Please don't be offended by this, it isn't intended to rile you in any way.
I am only after some clarity, as I perceive your language to be confusing terms mightily and so making things seem more complicated than they end up being.
What? Taking the example of Apple (since they make their battery ratings easily accessible, but other manufacturers are similar), iphone batteries are rated to hit 80% at 500 charge cycles, and ipad/macbook batteries are rated to 1000 cycles [1]. Assuming you discharge your battery from 100% to 0% every day (which is at the upper end of average usage), iphone batteries should last ~1.5 years, and macbook batteries around 3 years.
Apple also has a pretty good battery replacement service, at least in comparison to other manufacturers. When my iphone battery wore out after ~3 years, I shipped it to Apple and paid $60, and they sent it back a few days later with a new battery. My macbook battery lasted ~4 years of heavy usage, and they did the same thing for ~$200. A user-swappable battery would definitely be easier (and cheaper), but the service they offer is good enough that it's still feasible to get a replacement and keep the device past the battery lifespan.
If the hardware is actually, physically incapable of running later versions (AKA your Chromebook would crash and burn on boot), sure.
Any other case it's corporate greed and/or laziness.
The ?. operator was included in Edge, Safari, Chrome and Firefox early 2020. According to caniuse.com, only 90% of users have browsers that support it... but depending on who your audience is, it might be much less (e.g. if you target schools, or government, there might be computers locked in older OSs or browser versions... at least that's the case in my country).
Yes, they should, because these are the same people doing both
It is not a coincidence that "technology evolving" results in obsolescence. It is true that it is additional effort to support old devices, but it is a finite and feasible amount of effort.
Plus, old devices are hard to support in part because of decisions made in the creation of those old devices that make them hard to support. Like many other engineering things, if companies decided to get better at supporting old devices, it might be hard at first but it would get easier and easier as they got practiced and built solutions around it.
1) Chromebook is a "secure platform" => including drivers, firmware, etc. etc.
2) Supporting "security" across the browser is the first point, but additionally, there's security required across the whole hardware footprint
3) "when it's too expensive to keep track of / backport security fixes" or "the latest kernel won't build anymore" => "Sorry, your device is obsolete."
4) The rise of evergreen browsers (specifically chrome-monopoly) is pushing the definition of what is worth updating / monkey-patching / transpiling.
There's "ways" to update "stuff" but at that point you're basically using it as a linux device (subject to _linux's_ security and update stance) instead of a chromeos device.