First off it's not extreme, there way of getting around performance issues is effectively working around DX11, so they put a lot of time and money into performance improvements(which win a lot of benchmarks) but the real world consequence is worse actual problems with games at launch because the driver has become much more complex. SO time and money spent to win benchmarks, give the user a worse experience and once all games are DX12 it's entirely wasted effort. No, not an extreme statement, a complete waste. I'm sure there are millions of Nvidia users who would have preferred a more stable play through of Witcher 3 than for some benchmark to be ultra optimised with a complex driver.
Their biggest real world gains from more efficient DX11 drivers have come in API benchmarks.... ooooo, worthwhile.
Second, using Mantle and 285 as reasoning for DX12 is fundamentally flawed. It was proof of concept, with extremely little work(devs have repeated this for all DX12/Mantle projects) they got it working with the available hardware. It wasn't a market encompassing solution, it was a beta API where they focused on a small subset of hardware and features. by the time the 285 was coming out DX12 was confirmed, Mantle development was done basically by that point. Devs don't go out there to support unreleased hardware at launch nor when they are effectively making a proof of concept to they need long term support.
AS for the larger/smaller devs, it's still based on the argument that it takes a lot of work for every card, it doesn't. However it's still wrong, large devs won't have issues, medium/small devs will mostly implement one of the larger engines available which will have DX12 support by default, the smallest devs making indie games aren't making games that are performance dependent in the first place, they aren't remotely limited by DX11. A lot of indie games come out using DX9, they aren't relevant to the discussion.
Precisely and completely incorrect... as usual. DX12 in no way at all causes devs to become more dependent on 3rd party libraries. Was that just an excuse to mention gameworks and dependent in the same sentence. Also DX12/low level api, one of the fundamental driving features is precisely that it will take LESS assistance from hardware vendors to achieve what they want to do. A slimmer driver and no black box DX to cause lots of issues they can't identify themselves. Many/most of the problems with finding issues with games is that the dev has to talk with the hardware vendors and MS/DX people and they all have to work together to find some way to get it to work. With a slim driver, way more access and a low level API they can directly find and solve problems themselves with no waiting around for answers from e-mails.
This is actually where the smaller devs gain the most. Where lets say Rockstar are a huge important dev and will get priority access from AMD/Nvidia and help from MS re DX problems, small dev Indie Company B, will send a request for help that MS, AMD and Nvidia don't have time for but can't find a solution on their own. With DX12 a smaller dev has far more ability to fix it's own problems with far better transparency and better tools.
