What I'd class as major would be some third party gaining access to NVIDIA's RTL designs and source code for their drivers for current and unreleased GPUs, but this hack doesn't sound remotely close to that. Luckily.
By whom? I'd certainly class it as major if their website could distribute malware instead of the real drivers, as that impacts everyone. Stealing nvidia's proprietary designs impacts only them.
I visited that page a few days ago to setup a new system which is, at the same time, supposed to be very secure (the proprietary drivers being one of the weak points indeed, but can't quite get around that if the GPU is to be fully functional). If this was compromised then I can start over and have a bunch of passwords and private keys to rotate.
Ransomware operators are not that clever, they go for low hanging fruit. I mean, yeah, by all means, do recon on a system you just pwned and try to do a supply chain attack, but it's outside the range of these operators. They only have a hammer, and everything just looks like a nail.
That is an understatement. 65nm is ten times larger than what NVidia is currently using. That means the area would be 100 times larger and any signal distances 10 times larger. And keep in mind that NVidia GPU designs already take up quite a bit of area on modern nodes.
So you'd likely have to cut it down to a 100th of modules which would run at 10th speed.
When you design a CPU or GPU, the RTL, like the core pipelines, schedulers, and various buses, are designed from the start on a certain manufacturing process where they're expected to work correctly at specific frequencies that are fast enough to feed the pipelines at the right timings, in order to get the top expected performance. Failure to meet the fabrication process expectations means the RTL design will perform much worse than expected in practice.
That's why many of Intel's past designs sucked so bad in the performance and efficiency category as their 10nm manufacturing process fell behind, so they had to scale their newer designs back on the aging 14+++++ process, which caused those CPUs to flop big time.