sstelkar Can you please tell me your years of experience in shader programming.
Hard to determine precisely 🙂. I've been tinkering with shaders on and off at least since OpenGL fixed functionality pipeline got officially deprecated with release of 3.2. standard. Can't remember exactly when that was.
sstelkar Also since godot 4 has switched to vulkan, what is the future of godot shaders in coming years?
Shaders are pretty much the only way to control GPUs. They won't go anywhere in the foreseeable future. Vulkan doesn't introduce any new shading languages as there's really no need for it. It supports a number of established and proven languages like GLSL, HLSL, OpenCL... Vulkan (and GL for that matter) will always compile any of them into same platform-independent assembly-like intermediate language SPIR, which can be easily translated by hardware drivers to actual GPU machine code.
Since Godot's shading language is basically GLSL with some "macros" added on top. Switching to Vulkan really makes no difference regarding its usage. GLSL is here to stay.
If you ask this to see if it'd pay off to learn GLSL or a similar language, the answer is - yes if you're genuinely interested in computer graphics programming. Almost all shading languages are very similar to C. So learning C may actually be a worthy time investment. It will introduce you to low-to-mid level programming approach that's very useful for games/graphics, as you often need to code close to hardware. But even more important is to learn the relevant math - trigonometry, vectors and matrices (linear algebra), and basics of calculus.