IMO, the single best thing MS ever produced was OneNote and I miss it in Linux. They had a linux version for a while and then stopped supporting it, but I cannot find anything similar for Linux. Joplin is probably the closest thing to it but try dragging a PDF into and watch it not know what to do with it. It is so hard to get anything formatted like I want it. In OneNote, colors, images, highlighting, links etc are no problem. I used to copy things like color palettes and other graphics I liked into it and it was so easy to organize.
I have tried SimpleNote... I entered one note and tried to bold the heading but there is no ctrl-b or i or u... You have to use markdown. Markdown? You mean ** before and after the heading to get it bold? Come on. How can you even publish a note taking app that can't bold or italicize something?
I finally found Trillium Notes. It's a pretty awesome little app and for someone like me, who lives by taking notes and making lists, this is finally addressing most of my needs. It's still no OneNote but at least it has a easy to use interface and takes attachments, displays PDFs and even can handle process flows. More importantly, I am able to easily categorize and organize all my stuff.