True, and it's great that they don't block those (they absolutely could).

But those are plugins and aren't as easy to use as the integrated sync. Obsidian wants to have their sync to be the easiest to use, and the easiest to discover.

If they went FOSS anyone could just create a rebranded fork that includes their sync instead of Obsidian's sync. Even GPL wouldn't stop that, if the competitor would just keeps their product open source too.

You're replying to the CEO of Obsidian btw ;P

https://news.ycombinator.com/item?id=48088576