Stable binary driver ABI. Hardware monoculture. Expensive driver certification program. Letting hardware vendors release binary drivers without releasing the corresponding sources. An opt-out automatic update mechanism.
(Disclaimer: I work at Google, but not on the Android team.)
However, to say that HW interfaces on the PC have been stable since the age of IBM PC clones is a joke. In the DOS days, users manually had to manually set IO memory addresses and IRQ levels. Early Windows sat on top of DOS, so still had to do it there. Plug'n'Play didn't show up until Windows 95, and even then it was hit and miss. Some devices worked, others required manual configuration. RTM Win95 didn't support USB, either. That took the equivalent of a service pack (although, IIRC, they went by a different name back then. I want to say OSR1 added USB 1.1 support). Windows drivers didn't really get friendlier until the push to the NT kernel & it's HAL. Win2k had limited, but good support. WinXP got better. Vista was a step backwards. Win7, 8 and 10 have incrementally improved on Vista. Even on Windows 10, though, I have updates that "forget" a subset of my USB controllers. Windows doesn't know about drivers for my HOTAS. Most recent windows updates cause it to forget about my secondary monitor. Half the time after an update, my USB keyboard doesn't work (I have to login on my desktop using an on-screen keyboard to correct settings). I'm probably one of the only (or a small handful) of people that have a Geforce 690 & 1080 in the same system. Sure, PC might be better in that most peripherals go over USB. But, not all USB devices work with a generic driver, and Windows often doesn't include non-generic drivers for all but the most popular devices.
The core system of PC is highly compatible with OSes in pretty much all directions. (Well now even if I don't ignore the non-PNP ISA configurations stuffs, it does not really change the situation: those were not for core system stuffs)
Then you have drivers for various bus controllers and peripheral, some of which are crucial for using your PC in practice, but as soon as the necessary driver exists, loaded by the kernel way after the core boot, and highly abstracted on all modern OSes (it only access the HW through functions abstracted by the OS)
For non-ancient PC, you even have with ACPI some abstracted functions, provided by the HW, and used at the runtime by the OS. It's to be considered as part of the core plateform, as if it was a pure HW interface, given what we are discussing about. The NT HAL, btw, is a vestigial of early NT years, and is of zero interest for the purpose of PC compatibility today (there is only one HAL that is in use on modern PCs, and IIRC switching the HAL was not even enough when multiple were in use IIRC, other MS binaries still needed to be recompiled -- so the NT HAL is merely an internal detail that bring no consequence in backward or fw compat as far as decoupling of binaries and their update of a partial subset in a system is concerned)
Now the situation for ARM SoC for Android is NOT the same. You just don't boot a generic ARM Linux kernel to driver your random ARM SoC of your random phone. Because even what could constitute an equivalent core system as what exists for PC, follows no standard.
The kids today don't know how easy things are with unified drivers for audio on Mac OS etc. I mean, even USB coming out was amazing instead of serial devices and guessing the COM port? Which LPT1?? And dial up etc etc so easy now.
With PCI and later the OS can ask each device on the bus to ID itself and thus figure out if it is a known device type or not (and if not, ask the admin to install drivers).
On ARM You have things sitting off various buses that expect the kernel to know what they are and how to talk to them from the word go.
It has gotten better as now there exist something known as a device tree that can be read by the kernel at boot. But not every SoC provide support.
Heck, if you crack open the ARM based Windows RT tablets you will find quite the odd duck of an ARM SoC inside. One more reminiscent of a x86 PC than what you find in your average Android device.
IMO the key point out of the things you mentioned is the hardware monoculture, because that definitely does help people get Linux running (and keep it running) on new hardware. I'm skeptical about most of the others.
But the reason I brought it up is that Fuchsia OS will have a stable driver ABI.