I'm sure more than a few of you know that Linus gave Nvidia the finger and more a few years back and with good reason.
Yes, they wanted to connect to the kernel in ways they weren't allowed to. Changes were made in Linux that forced them to comply. Nvidia made the necessary changes on their end in relatively short order, so short in fact that by the time I actually got a distro with an affected kernel the driver had already been updated, so there was zero impact to me — an Nvidia user. No question that it was sleazy, though.
I used to be an Nvidia user because I dual-booted, and AMD drivers for Windows are hot garbage (and before AMD, the ATI drivers for Windows were the same.) Now I am an Nvidia user even though I don't dual boot, because CUDA is required for some of my use cases, and ROCm only supports a small subset of cards. The AMD drivers for Windows are still trash, but the OSS AMD graphics driver for Linux is great so the only thing that needs to happen is that my use cases need to be less CUDA-dependent or AMD needs to get serious about supporting ROCm across all of their GPUs, and then I will start thinking about buying AMD GPUs which I have regretted every single time I have ever done it in the past. I have seen crappy drivers cause crashes with "their" (ATI's and then AMD's) hardware since Windows 3.1 and the Mach32.
Nvidia can't release GEforce drivers as OSS because they contain Microsoft code. This was part of the deal for getting their chip into the original Xbox. As you yourself state, they have released drivers for their ARM-coupled GPUs. You may not be happy with the way they released the sources, but they did release them and they are usable. Don't unpack them over the top of the prior release and you won't confuse yourself. If AMD were competent at software, then Nvidia would be far less popular. They aren't. That's why their Windows drivers still cause crashes. If you have a simple use case and only want to run Linux, AMD GPUs are totally viable and probably even your best bet. If you want broad application support for GPU acceleration, or if you want to dual boot, Nvidia is still the best choice by far. I use AMD CPUs exclusively, but I also use Nvidia GPUs exclusively. These days (and for some years now) the Linux driver keeps up with the version of the Windows driver. The only missing feature is interleaved SLI, which I no longer want to use anyway, so it's not bothering me.