@owlyph I merged the old thread here as it all relates to the request to open source Obsidian. I don’t plan on getting involved in this discussion, but I do want to point out a few things that you might want to consider.
As it was mentioned above this requires a lot more time (and experience) to make it work. I don’t see the point of open-sourcing if the devs don’t have the resources to accept PRs and manage issues. This could actually end up being counter-productive, with other apps profiting from the open-sourced code instead of helping make Obsidian sustainable. As for contributing as part of the community, there is the plugin API which already enables you to contribute and help others.
As @tusharc mentioned, I think you’re underselling the advantages of plain-text files and how powerful that is. Data-lock in is about your files. If Obsidian were to disappear, I would still be able to use them without major problems. I don’t think there is anything specific to Obsidian related to content or folder structures that couldn’t be fixed with a script later on, but it might be worth it to keep that in mind and make your notes software-agnostic if that is a concern of yours.
Plugins are also publicly available, so you can have backups of them in case you want to recreate their functionalities in other editors if Obsidian disappears. You are also welcome to contribute to them to make their formats more portable or compatible with other editors as well.
Given that you are already aware of these open-source applications and their limitations, I would really recommend focusing your contributions there. There are other open-source alternatives you can also consider: Foam, Athens research, dendron, (among many others that keep coming up). Adding the functionality you are missing to the (open-source) editor of your choice would make a great contribution to open-source software and provide a backup for your processes if Obsidian were to disappear.