You seem to be forgetting that Steam Machines existed back then, and Wine barely supported D3D9.dll in those days. Valve and Codeweavers did the majority of the work bringing up DXVK, without which there would be no DX11/DX12 game support on Linux at all. It's not exaggeration to say that the Steam Deck would not have been a success if DXVK never existed.
There's certainly cause to celebrate Wine's accomplishments reverse-engineering Win32. But it's far from the only thing required to get games running, and I think you've oversold it's importance.
> Lots of Linux ports have been cancelled since this is becoming the norm..
Shocker. Given the way MacOS is treated by game developers, I'd much prefer translation be the focus instead of courting native ports that will break in 2 months from a glibc update.
> to sell a handheld running wine on battery I'd be pissing myself laughing from how inefficient and terrible that sounds
I'm not sure why. The GPU is where the lion's share of power consumption happens, and Proton uses the same Vulkan API that modern, native Linux titles target. Sure, you have to wait for shaders to cache, but you have to do that on most Windows PCs nowadays too.