My Answer:

Yes, this is how I look at it.

My approach to world building is the sandbox method.

By that I mean, I build my world, like I was building a sandcastle in a sandbox, and than I drop my characters into that castle and see what happens.

So for me, it's I spend huge amounts of hours writing up vast detailed descriptions of everything: countries, cultures, streets, forests, rooms. And when I've got the world written out the way I want it, I start writing my characters into those scenes. Than I write conversations between characters, and interactions, and before I know it, a story is happening, the characters are off going places and doing things.

So, it's sort of the snowball method of writing, only I do it with worldbuilding sandbox.

I end up, with a finished draft, that I can polish and publish.

So, for me, the way I go about worldbuilding, writing down everything in descriptive scenes, and than later rewriting those scenes with characters in them, and then fleshing those out into a full story, for me, worldbuilding IS writing, because I'm literally writing the scenes of the world down as I create it, and those scene will end up in the finished novel a few months later.

So, I would say it all depends on how you go about your world building process. If you are charting maps, and making lists of names, and drawing/painting pictures, well, than I'd say it falls more into outlining, but I'd still call it part of the writing process if those charts and maps and drawings help you sort out your ideas and get you better able to write your story.

This is very true. 

Often, people say they are writing, when they are only world building and world building and world building and world building and world building and world building and they have yet to create a character, don't have any plot ideas, and really have nothing at all that could be considered a novel.

Worldbuilding CAN be a part of the writing process, yes, but, it's not ALWAYS a part of the process.

There are many stories which don't require worldbuild, just as there are many world's build which never get written about.

Thus it is possible to write a story without building a world and it is possible to build a world without writing a story.

So with that in mind, the answer is both yes AND no, depending on the situation.

Yes, worldbuilding is a part of writing, IF, you are writing a story and need to flesh out the world so you can better visualize what you are writing.

But also, no, world building is not writing, if you just build and build and build and never write about the world you built.

If you enjoy worldbuilding as a hobby or for your TTRPGs then sure worldbuilding is a good time, but if you want to make money off it then you're wasting your time... This can be true, but, not always.

but if you want to make money off it then you're wasting your time

Not nessacarily. Again, it depends.

If you enjoy worldbuilding as a hobby or for your TTRPGs then sure worldbuilding is a good time, but if you want to make money off it then you're wasting your time... but...

Every Dungeons and Dragons, Pathfinder, Warhammer, GURPS, etc game guide was written and what are those? Huge world written for gamers to play their games in. They contain no stories, because the players write the stories themselves, but each campaign setting book (and 4th edition DnD alone had more than 2,000 of them) is an entire world that someone spent a lot of time building. And so, building massive worlds, without writing stories about them, is in fact a career option you can make money with. Thus, it is possible for  worldbuilding without writing a story, to not be a waste of time, even for those looking to make money from it. It all depend on what you do with the world after you build it.