Vulkan has a lot going for it these days, but IMO the problem with its future is that (a) it's too verbose to use without an abstraction on top and (b) vendors won't stop pushing their native APIs as a competitive advantage (Microsoft still pushing DirectX - often getting features a year or two ahead of Vulkan, Apple is pushing Metal, GNM[X] from Sony, etc.)

I think this means the future of graphics APIs is software abstractions around the truly native APIs (DirectX, Metal, etc.) - things like WebGPU, sokol_gfx, SDL's new GPU abstraction, and Sebastian Aaltonen's stuff.

Shame though that by the time you've gotten your first cross-platform triangle on screen in Vulkan you'd already be finished covering Windows and macOS via D3D11 and Metal, and with fewer total lines of code ;)

(D3D11 is not a typo, unfortunately D3D12 isn't that much better than Vulkan in that regard)

I know you mean major desktop platforms, but in terms of market share for real time 3D applications, mobile and console dwarf Mac and Linux.

Middleware runs on more platforms, with more friendly tooling.