Examples of this happening? The Samsung Galaxy phones (I forget which model) that had the bad battery design that kept exploding. Multiple updates were pushed out that, among other things, disabled charging of the battery and eventually that simply shut them down. There was also one that disabled many of their features before this happened.
ALL mobile phones have this "capability" should the manufacturer use it. They make and control the firmware updates sent to each phone. In a way (more by lack of action than by something done), it happens all the time, since the manufacturer usually won't bother to make more than a token few software updates before it gets dropped in favor of the next model or Android version (I've been corrected; they are supposed to remain updated for at minimum two years. This still seems short, though). This means that they become outdated sooner than their actual hardware specifications should imply. I actually know someone with a higher-spec phone than mine running a fairly recent Android who can't run some apps because said app expects Android updates for that version from the last 6 months and the manufacturer already stopped updating it (also, some manufacturers don't usually provide updates that fresh, period).
(I'm also told you can disable updates, but if there's a "device disabler" feature in some specific one, it's not like you're going to be told that. Usually you'd want to keep it updated, too.)
There are also numerous "find my device" apps and utilities baked into many phones, which can certainly do this (that's what they're for). Since this is done through the OS provider, we're forced to trust that said company won't just activate it themselves for some reason (or that some government won't ask them to do it either). You frequently can disable these, but again, most usually won't or won't even know it's an option.
As for desktops - it's very possible as well. Many do have "LoJacK" or equivalent enabled, which again has very low-level access to the computer (on some, it's even built into the BIOS rather than the operating system). There are few details available to the public, but it's quite likely that even with it "off" (that is to say, you've never activated it yourself) it can still be used at the option of the manufacturer.
Dell, for instance, puts it in the BIOS - https://duckduckgo.com/?q=dell+bios+lojack
Making matters worse, Intel, AMD, and ARM produce various "security" (usually more for the security of media streaming companies via DRM/rootkits-by-any-other-name than security for you) or "management" systems for their CPUs that are used in enterprise-grade machines to monitor, locate, control, and manage said machines. This hardware module has beyond-top-level hardware access over the Internet (it can read your RAM or hard drive without your knowledge or ability to detect, and attempting to completely remove it will cause your computer to shut itself down on its own after a few minutes of usage).
(NOTE: I was not referring to TPMs here. I think it can be argued that those are beneficial. What I meant was sandboxing like ARM TrustZone or equivalent, where usually the only or main thing running on there is your DRM engine. I suspect, but do not know, that tracking software like LoJack would also be run in these. Windows 11 will now be using this feature to "protect" certain OS components as well, but my personal suspicion is that this is also to protect against pirated Office installs and to better secure their DRM.
I'm not sure about how long ARM (TrustZone) has also been doing this, but theirs is present in all smartphone-grade processors produced by them at minimum. Even a lot of their microcontrollers have some version of one of these features.)
Interestingly, modules like ME are also present (but allegedly turned off via software) in every single consumer-grade CPU sold from the former two manufacturers since approximately 2006.
I've looked more into this, and if Wikipedia can be trusted on this, it runs on a separate physical chip near the CPU and presumably does have backdoored access into at least the Ethernet connection (probably not Wireless, though):
The ME has its own MAC and IP address for the out-of-band interface,
with direct access to the Ethernet controller; one portion of the
Ethernet traffic is diverted to the ME even before reaching the host's
operating system, for what support exists in various Ethernet
controllers, exported and made configurable via Management Component
Transport Protocol (MCTP).