Intel Arc owner for around 10 months here. There seems to be some misinformation and misconception here so I will try to clear them up:
1.
And while I'm already at it, your number for the GTX 1070 Ti is also wrong, because it also supports DirectX12 Ultimate, which means that it has to support at least Shader Model 6.5 too. (It actually supports 6.7)
2.
Also I think Intel didn't implement DX9 native support to cut corners, but because the don't have a 20+ year backlog of drivers with DX9 support and it just does not make sense to add it now, when there are barely any new games coming out that use DX9 and you can put the effort instead into more important things like driver stability and support for modern games.
3.
1.
I don't know where you read that Arc only supports Shader Model 5.1 but it is false, because in order to support DirectX12 Ultimate it has to support at least Shader Model 6.5. Additionally Wikipedia lists the Shader Model as 6.7, while TechPowerUp lists it as 6.6.GPU minimum requirements are generally not a question of "muscle" but technologies support.
Intel Arc A770 support Shader Model 5.1
Nvidia GTX 1070 Ti support Shader Model 6.2
Starfield seems to use a version above 5.1 and Intel scrumble to add functions used by Starfield to make shaders work correctly.
And while I'm already at it, your number for the GTX 1070 Ti is also wrong, because it also supports DirectX12 Ultimate, which means that it has to support at least Shader Model 6.5 too. (It actually supports 6.7)
2.
For around 6 months now the driver size has been between 600-700Mb, which is pretty much the same as AMD and NVIDIA drivers.. When Arc launched the drivers were indeed around 1.2Gb, but Intel addressed the driver size fairly quick.Intel tried to cut corners on so many ways (ie not DX9 native support) and now they pay the price by trying to fix EVERYTHING through driver updates (1.2Gb driver - wtf)!
Also I think Intel didn't implement DX9 native support to cut corners, but because the don't have a 20+ year backlog of drivers with DX9 support and it just does not make sense to add it now, when there are barely any new games coming out that use DX9 and you can put the effort instead into more important things like driver stability and support for modern games.
3.
Buy a crap GPU, get a crap experience.
A friend of mine recently got a Radeon RX 7600 and in the first week it had more problems than my Arc A750 on it's first week in early December. Arc GPUs are by no means crap, when they came out they had the best media engine on the market, ray tracing was competitive with NVIDIA and ahead of AMD and the same is valid for XeSS. Besides Intel didn't cheap out on VRAM bandwidth like both NVIDIA and AMD do nowadays. Since I have my Arc GPU I only experienced 2 games that didn't work, and every other game ran great, except for a few stutters in the first few months, which got fixed with driver updates. Outside of gaming I only had a problem with the GPU not detecting my second monitor at first, which I was able to fix after plugging it into my iGPU once. So far my experience with Arc has been pretty good.that's omitting the fact those GPUs have been nothing but trouble since they were released.