Urban Games are showing their dedication to Transport Fever 2, as they just today release a massive overhaul to the rendering system along with adding support for the Vulkan API. The first major update since July 2020 and along with a build for macOS it includes plenty of enhancements.
With Vulkan support now in, they didn't just remove OpenGL so thankfully anyone who has a card good enough to run Transport Fever 2 that doesn't support Vulkan isn't just left out in the cold as there's a switch to go between the APIs and it will fallback to OpenGL is the Vulkan extensions aren't around.
They also put plenty of work into the game to improve performance as a whole with rendering performance overall being improved, CPU performance is better overall across both OpenGL and Vulkan, they improved memory management on terrain textures, you can actually toggle Vsync in the settings menu now, support for the 5120×1440 resolution was added in, zooming in and out should be smoother, there's a new cable-stayed bridge type available and many more improvements. A full changelog can be seen here.
From the press release, they mentioned around half a million players so it's been quite a success for them.