Yeah, my current, main ideas txt file is something called "movies to watch.txt" —which does start with a list of movies, but then I added some random extended thoughts there temporarily and it has grown massively since.
So yep, I may be a good candidate for using OrgMode ;)
I tried out a demo of Notion (https://www.notion.so/) not long ago and was pretty impressed by their editor (similar concept to OrgMode, but wysiwyg, which I prefer if it's done well). It's actually really good (annoyingly you have to give an email address to try, and their other info. isn't nearly as informative as just trying it for a minute)—but I can't bring myself to use it because of the platform lock-in aspect. I want the data stored in a local file and that's it.
Edit: looking a little more though (was watching a video of table creation in OrgMode), I think the emphasis on editing plain text is going to be too off-putting for me: I do want a simple local file that multiple programs could work with, but the text editing required for OrgMode seems way too cumbersome unless you're already an emacs devotee—which I'm not (largely because I've had RSI issues, and rumor is emacs isn't the most ergonomic text input style).