I have about 150 notes in my collection, along with ~250 dailies, so copying everything over by hand was out of the question. I could not find an acceptable ready-made solution, so I wrote a simple Ruby script, that leverages Pandoc to do the org to markdown conversion. The repository is here on GitHub.
In the end, though Obsidian seems like a quality piece of software, I love Emacs and org-mode too much, and decided to stay with org-roam. It’s good to know that I am not locked in, though, and that I can choose to export my entire library at any time.