A LONG time ago now I went kinda all-in on OrgMode in emacs. I'd dabbled with emacs for years (I'm 52) but it never "took" for me as a full-time editor for lots of reasons.
However, my endless search for a proper to-do management tool eventually led me there, because what I really wanted and needed is more or less Org's whole reason for being: being able to intermingle notes and TODO items, and then being able to generate a dynamic "view" of the TODOs from across a corpus of notes.
Most Todo apps I'd tried, including lots of them based on the last big geek productivity obsession, GTD, had only paltry note features. That didn't work for me or my job AT ALL. I wanted One Trusted System, and Org gave me that.
Now, if I was coming to this need NOW I think I'd probably look more closely at linked, syncing tools like Obsidian. You can mimic the "show me my todos" thing with Obsidian, though it's less organic than with Org -- but on the other hand, Obsidian has mobile apps that are very good, and I have yet to find an iOS tool that meshes will with my work style in OrgMode. Obsidian also has a MUCH MUCH LESS ONEROUS learning curve. I love orgmode, but I would absolutely not suggest that most people undertake learning emacs just for a productivity tool. ;)
(I still don't code in it.)
Obsidian, for example, takes over 2x as much RAM on my computer as Emacs does, which is crazy.
Add to this the fact that they all have to work with basically the lowest common denominator of interfaces, which means they're consistent across platforms but also completely eschew anything native on any of those platforms. In the Mac world, this is especially egregious because we as a tribe tend to actually LIKE the way the Mac does things.
There's a phrase popularized by Brent Simmons about this: Mac-assed Mac apps. See
https://daringfireball.net/linked/2020/03/20/mac-assed-mac-a...
And as I noted, it doesn't feel like a Mac app, either.
Both issues are pretty big negatives for me, even thought I have the RAM to run fat things, but my issues are not YOUR issues. If Obsidian is working for you, there are advantages to that.
Do you use it?
The workflows people imagine around them are complicated.
I use it in a way that is similar to the 16 minute video posted elsewhere in this thread, and it works well for me.
Biggest benefits for me are:
1. Finding references, before using obsidian I would recall reading something somewhere but would be unable to find the so source
2. I remember stuff I write about better. I use it a lot for work, software engineering, so I summarize new ideas and concepts as notes which makes it so much easier to remember and understand
The important part of that is that it forces me to break ideas down into manageable chunks. I can't make a note about "everything you need to know about react 18", but I can make a note about "React 18's useTransition hook prioritizes rendering of user input".
3. It's fun! I've always enjoyed writing, and always enjoyed customizing editors and IDEs, obsidian is a great fit for that. It's exclusively for so writing and organization, so now I have two main programs, my coding editor and my writing editor.
4. The program also just works really really well. Evernote is bloated and has weird updates, emacs is insanely complicated and maybe just a little bit too powerful? Roam and friends are too chaotic for me, I don't function well with 0 structure. All simple markdown programs I used lacked good syncing, although sublime text with Dropbox came close. But obsidian just syncs perfectly, and has a very performant application on all devices I use, and yes I'm crazy enough to use all three of windows, Linux and Mac os as well as mobile... I like variety
Still, a lot of what obsidian does can be achieved with alternatives. Sublime works well with Dropbox, if you're in the apple ecosystem then Apple notes is great! Regular text editors or traditional note taking apps are still very viable.
In the end it's about what you do. If you are a knowledge worker, or even more particularly a researcher/ academic you need a good solution for organizing your references, notes, ideas etc. Obsidian is a great choice for that.
Otherwise don't bother unless you find it fun or interesting.
They never stuck and felt more of chores than frameworks.
I think that the first thing you need to clarify is the goal of your notes and then try some relevant system and adapt it.