Obsidian is free to use, and they make their money from offering additional sync-service and good will of the users. I don't think open source would impact it much. Though, it would bear the risk of a hostile fork, maybe to include a free to sync or something. I mean the obsidian-devs have some bad history on that front.
But at least they should give some guarantee to Open Source it if there were no significant update in a while, similar to how Qt and KDE have their agreement. Or at least they should make the source available, so people can contribute or move away easier in case of problems.
But at least they should give some guarantee to Open Source it if there were no significant update in a while, similar to how Qt and KDE have their agreement. Or at least they should make the source available, so people can contribute or move away easier in case of problems.