So yeah, Obsidian or even Logseq could be a good shout.
Seeing as you specifically referenced wiki software, I’d cast a vote for Tiddlywiki. There’s a lot you can do with it, right down to mind-mapping.
If you’re feeling adventurous and want to focus on the “visual thinking” side of your note-making and mind-mapping while retaining some of the features offered by contemporary knowledge management tools, maybe take a look at Heptabase or Gems.