I can't imagine too many ways that a backpack or piece of furniture can become accidentally damaged by "user error." Remember, so many people try to misrepresent their own mistakes (perhaps because they didn't understand what happened or they didn't realize it was their own fault) as product defects that the phone manufacturers all had to add things like internal liquid sensors to their devices.
On another note, many of my non-technical friends conflate Android OS software problems with device defects (e.g. "my phone died" actually meant that they had 300 running processes because they never learned how to close running apps on Android -- which to be fair is a PRETTY buried feature that doesn't lend itself well to user discovery; the number of people I see that don't realize they have to manually close apps on their Android phone is shocking). It's probably the reason there are so many ways to buy "refurbished" devices.
Needless to say, if Apple or Google started honoring a lifetime warranty, they'd lose a lot of money pretty quickly.
Maybe on a 2011 device with 256MB of memory and Gingerbread this was true, but memory management hasn't been a problem on Android phones for a few years now. The memory management has improved in parallel with the amount of available memory, to the point where the device can actually perform worse if the user goes mucking about and closing apps manually. With Marshmallow and Nougat it has become even more efficient.
The OS already uses 950M of its 1GB of RAM.
Remember, memory is like a keg of beer, if everyone drinks it all, it's gone regardless of how you "distribute" it to people into smaller sized Solo cups or whatever.
I can think of a few things that could help but not solve the problem, but the crux of the problem is that it's still a finite resource:
https://developer.android.com/topic/performance/memory-overv...
Working against that, you also have Gates' Law.
Anyway, it's my understanding that Android uses custom heap size limits to help keep things running smoothly. This combined with efficient garbage collection makes for a generally smooth user experience on a constrained device like a phone or tablet. Android will cache, and later kill, processes that aren't being used, to free up memory for active processes. Memory may be a finite resource, but not in the way you described; it's not permanently used up and can always be freed for foreground tasks.
This article is one more piece of news that makes me glad I excised Google from my life almost completely (I haven't found an alternative to my Nvidia Shield TV yet, but I'm looking).