I use Obsidian for note taking and pretty much anything I need to write down. I like it because they're just markdown files and it's easy to back up with Git.
It also has lots of extensions too. Including vim!
Logseq. It's free, open source, actively developed, has mobile apps, and most importantly your notes are text files stored on your computer.
It replaced the following apps for me:
The good thing about notion is that yiu can access your notes on your phone, tablet, ... . However, the user experience is so bad. Notion has very slow UI and it hasn't got any better for a couple of month.
Now, I am back to obsidian and sync my files to Proton Drive. This isn't comfortable though because proton Drive has no sync features yet, but it's good enough for me. Most of my work is done on my laptop anyway.
You can use git obsidian plugin to automatically commit new notes and then use gitbook to automatically pull that notes and edit them (and commit them again) on your phone.
Sadly I haven't found anything as convenient as Onenote. I take a lot of screen clippings from pdfs/powerpoints/zooms/articles and paste them into notes to then rearrange, annotate, write around them. Ctrl-E opens search across all my notebooks and notes including OCR from the images. Onenote takes care of sync to my phone and other devices.
It also has lots of extensions too. Including vim!