I just shifted from Logseq to Obsidian over the last couple of weeks. One of my reasons for doing so is that while Logseq does technically store your notes as local markdown files, there's so much added on top of that, that I can't really open my notes folder in Typora/[markdown editor of choice] and have a smooth experience reading my notes. The underlying format might be open, but there was still lock-in. Obsidian seems much better for that - there'll always be a tradeoff between features and portability, but I do prefer Obsidian's balance.
Once you start getting into your notes you quickly run into common markdowns limitations and it's super simple stuff like centering images or adding captions. Then you choose to either flavor your markdown or use HTML and it's no longer common markdown.
I wrote a very rough Python script to help me move my graph over to Obsidian - if anyone else is in the same boat, feel free to try it out https://github.com/NishantTharani/LogSeqToObsidian
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