> So open sourcing would not harm any of those income streams.

Obsidian's income streams are based on Obsidian having easy-to-use easy-to-setup ways to sync and publish built-in. If Obsidian were open source, someone could fork it and remove or replace those built-in methods, which has the potential to harm their income streams. Whether it actually would and by how much depends on a lot of unknowns and is all just conjecture, but _if_ such a fork became somehow more popular than Obsidian proper, that'd definitely affect them.