Earlier quoted context omitted.
Which really begs the question: why not have it open-source at that point? Obsidian isn't making money from things hidden in the code, but rather their Sync service. Might as well open-source it (and perhaps get more people helping with the development), keep the Sync service, and stem competitor projects like these in the bud.
Because then someone might fork it into a new product with their own sync service.
The whole data structure is designed to make this easy.
I chose Syncthing for this purpose, and it is free and works flawlessly. You can even trivially disable their native sync, as it comes as an internal extension.
Mozilla could have avoided so much drama with Pocket, VPN, AI features, etc., if they just were as transparent and liberal with critical first-party services as Obsidian is.