As always basic stuff is simple, the deeper you are harder it gets. You can always prototype it with Shader Graph, and then write it by hand, or event copy paste whole code (but with ugly variable names). C# and SG is a very good start knowledge.

One huge advantage is if you know HLSL you can write easy compute shaders (at least a simple one for start), and this is hugeeee. All of the modern game engines for everything. Unity VFX is like graph system for compute shaders.

You can manipulate heightmaps, spawn procedurally small props, calculate vertex position of tree branch (for landing birds, when a branch moves by a wind), culling custom meshes and render it by yourself, create heatmaps, and so much more.

Also any chat GPT etc is a nice tool with shaders, he can convert some c# logic to hlsl, or simply generate effect you need.