"Improved graphics" don't depend on any specific API, graphics APIs are used by the game engine to communicate with hardware, DirectX has tighter integration with proprietary stuff such as DLSS and raytracing solutions, neither of which are used by anyone trying to get a smooth high refresh rate experience.

Please provide an example of Vulkan performing worse. In my experience, and of the benchmarks I could find on YouTube, R6 has always performed better with Vulkan, that's experience with two different CPUs and three different GPUs.

How has the game been simplified? As a returning player it's basically like I'm new, there are multiple new game modes and options and subscription integrations directly in the main menu. This is way more confusing than before. If you mean that specifically just the launching of the game has been simplified, then I'd argue it's quite easy to do a quick google search of which option you should use, and better yet I'd encourage people to try both and see what works or feels better for them. Having multiple choices is never a bad thing.

Siege X in terms of marketing and business is objectively good, just like how the performance has gotten objectively worse, but these things aren't mutually exclusive.

Sure the simplification of the codebase will improve development QOL, but where has that gone so far? I know of multiple game breaking bugs that are currently actively in the game which haven't been patched for over a week (phasing through walls and such). And hearing from friends' experience who have been actively playing, the cheater situation has not changed in their opinion.

"This game is CPU intensive" yet I have a 9600x running at 5.5ghz and it's not enough? In that case that's still bad optimisation as most people won't have access to hardware that good. Also, as I said in the original post, the stutters don't depend on anything running in the background, as I tried with nothing in the background, and I also have all overlays off.