I tried Obsidian, Zettlr, Standard Notes, Dendron, even tried taking notes in Scrivener.

In the end I bit the bullet and started using Emacs + Org-Mode/Org-Roam. The flexibility and customization are unparallelled. I use it for to-dos, for random scribbles, for in-depth musings. Categorizing thoughts and linking them together is so much easier than any other software I've used.

The first few months are really tough, and for someone who has never used Vim or other terminal style interfaces before learning shortcuts took a while. But after 6 months, I can't go back.