* many drivers will be closed source; open drivers are a major achievement of Linux
This is only partially true, simply having the source code for a driver doesn't mean you can fix anything given that overwhelmingly the hardware documentation isn't open or the drivers are talking to closed source firmware/binary blobs running on the hardware itself. It makes it easier to fix trivial problems caused by the OS changing, but it doesn't help when a problem is discovered in the underlying hardware/firmware/etc.
So, the open source doesn't help as much as you would like, given the original drivers are frequently written by the hardware provider itself, or some privileged contractor given the documentation under NDA. This has been a huge problem with the ARM soc's that are "supported" in the linux kernel. Frequently they don't actually work following any given update, and no one can fix them because if they have open documentation it frequently is missing large swaths of the actual registers and device theory of operation parts necessary to assure that any given peripheral works.
The source code of the Linux kernel portions is still a huge step in the right direction, even if it comes without detailed datasheets and and talks to proprietary firmware.
It still lets you continue to evolve the internal kernel interfaces without having to worry about the driver's existing ABI.
It still lets you fix most security holes, or remove anti-features that rely on interaction between the firmware and userspace.
Fuchsia, by means of facilitating real proprietary drivers, will take us back to the Windows era, where the OS must support 2 or 3 different driver models in parallel just to continue supporting existing hardware after it has been abandoned by the vendor (which typically means 1 or 2 years after its launch).
Yeah, my 10 year old laptop, bought with Windows 7, is now running Windows 10 latest, without any driver issues.
While my Asus netbook, bought with Linux on it, has lost the DX 11 GPU capabilities and video hardware acceleration thanks to AMD open source driver reboot.
Ah, Asus still pushes updates to Windows drivers on that specific model.
This is only partially true, simply having the source code for a driver doesn't mean you can fix anything given that overwhelmingly the hardware documentation isn't open or the drivers are talking to closed source firmware/binary blobs running on the hardware itself. It makes it easier to fix trivial problems caused by the OS changing, but it doesn't help when a problem is discovered in the underlying hardware/firmware/etc.
So, the open source doesn't help as much as you would like, given the original drivers are frequently written by the hardware provider itself, or some privileged contractor given the documentation under NDA. This has been a huge problem with the ARM soc's that are "supported" in the linux kernel. Frequently they don't actually work following any given update, and no one can fix them because if they have open documentation it frequently is missing large swaths of the actual registers and device theory of operation parts necessary to assure that any given peripheral works.