Tana seems vaguely similar to Anytype, but without any of that app's focus on privacy, security, and strong ethical values. Not that it might not be a good app, but I can't see switching from Obsidian for something that will eventually lose so many of the features that Obsidian already offers, for free (especially if enhanced with plugins). If I'm going to move to a piece of software for all my work, especially for my more sensitive stuff (like health information), I'm going to do so with a zero-knowledge program that hands me the only set of keys, and allows me to easily export my data to simple .md or .txt format.