I've tried Trilium in the past, and tried Obsidian this week. I fell in love with Obsidian instantly (even though there are a couple of key things missing [1]). This is entirely subjective, but the UI of Trilium actually gives me anxiety - I want my note-taking, knowledgebase to be a zero-friction thing of calm. Obsidian definitely is, I spent two minutes customising keyboard shortcuts to closer match Sublime Text where I spend most of my day and I was up and running, and in the flow when writing documentation. Trilium is the exact opposite of that. It's information overload. It reminds me of MS Word with all the toolbars open. Some people like that, but if you like a calm, focussed place to write or read documentation or notes, I'd go with Obsidian.

[1] For me Obsidian is currently missing anchor linking to headers within a document (which I know is on the roadmap), and scroll past end of document, as I hate my carat being anchored to the bottom of the screen when writing. Despite those things being missing, I'd paid the personal license within about an hour of trying it and if it turns out to be useful across a team I'll pay the commercial license for it too.