Why do you want to use Obsidian for that??
I have spent some time exploring both the official Obsidian forums, and their subreddit and the above tends to be one of the very most common questions I see, either as a response to someone else's post, or sometimes even as a standalone post just calling the whole community to task.
To be honest, it's a reasonable question.
A lot of people (including myself, I admit) want ONE APP that can do it all. Task management, meal planning, annotating PDFs, managing databases, calendaring, planning dungeons, daily journaling, etc, etc, etc... Wait a minute, I feel like I forgot something.
Note-taking, you say? Never heard of it...
The people asking why we would try to use Obsidian (or any one single app) for all of those things have a good point. There are other apps that do databases, calendars, and task management way better than Obsidian. They warn that we're setting ourselves up for disappointment as we'll be exerting more effort to achieve poorer performance. But where they're often wrong is in their assumption that we don't already know that.
But why would you make that trade off willingly?
For me, it's simple. When I close one app I lose about half of the attention I had directed toward whatever it was I wanted to do next, which means there's only about a 50/50 chance I get Todoist opened before I forget what I was doing.
CONTEXT is everything
Some people get very upset with the idea of a second brain. And I get it, especially as it has become kind of buzz-wordy over the last couple of years. And if you want Obsidian, or any other program to only be a place to write and store notes (locally-stored and in a non-proprietary format), then you're welcome to use it that way.
But if that's all I wanted, I would have stuck with Google Docs, OneNote, or Evernote. Those served me very well when it came to just writing notes or collecting information, in the case of Evernote, back when the web clipper still worked right. Rocketbook can even sync to any of those options right out of the box. They were great at building up a stock of information. Problems only arose when I actually needed to ACCESS specific parts of that information. For things I didn't look at all the time, I could never remember where I saved it. And that's assuming that I even remember I saved it in the first place.
For me, the number one strength of Obsidian is that it can serve me information that I need when and where I need it. But to do that, it needs me to feed it all that context (which requires plugins and yaml and databases, etc...), and once I close Obsidian, I lose that greatest benefit.
As long as I stay in the app, Obsidian can truly be my second brain. I don't have to worry about navigating the file system in my head.
Learning for its own sake
There's one other piece to this puzzle.
This is also where things get a little tricky. I recently saw someone talking about these kinds of tinkery-tech setups, and warning people against putting time and energy into learning "skills" for these projects that won't actually be applicable in other parts of their lives. Not only Obsidian, but a number of my other hobbies.
And this is good advice. If you're trying to maximize productivity, spending limited brain power on single-use education is a waste. There's always plenty of things to learn that will directly improve your productivity.
But c'mon you know I'm never trying to maximize productivity. I don't even like to use the WORD productivity if I can avoid it.
Thinking about thinking, or learning about learning
It's a lot like spoken language. Where my language is subject-verb-object and the language I'm trying to learn is subject-object-verb, just knowing about subjects, objects, and verbs, and how they relate to each other allows me to better adapt to the new SVO structure once I know that's how it's done.
Instead of cautioning against ever learning a single-use skill, what I would warn is:
a) Only do it if it's fun. Sure the projects can and probably will get frustrating along the way, but if you're not getting a net positive feeling toward the experience then it isn't worth it. There are other things you can learn that will be fun for you.
b) Don't skip over the hands-on part. You'll need to read some and maybe watch some YouTube videos any time you're learning a new skill, but you have to actually put it into practice if you want it to become a skill. Don't get stuck on the consuming part of learning; go get your hands dirty, even if it doesn't work at first. (psst, I'm talking to myself re: woodworking)
If you already have a task-management system that is working for you, then you don't need Obsidian for that. But also don't feel scared off by the people who don't like the way you're using their app. It's up to you to decide if the trade-off is worth it for you, and if the process is working for you.