Why not good Procedural Tutorials?

Hey everyone, i have a question. Why is there no good Tutorials about Procedural Terrain Generation? Only Assets, but i wan´t no asset because i will learn this stuff! I know it´s difficult but how we can learn this? The only Procedural Generation Tutorial Series that i know is from Sebastian, but it´s only for Terrain. Everybody makes only Terrain. But what is with Pathfinding later? Or Spawn Properties like Trees? Nobody make a Tutorial about this.

So, hope anybody have a Blog or a Course for this that i can´t find. But i google for 1 Month for this Stuff.

I´m ready to pay Money for this.

Sorry for bad English :p