I’ve used Obsidian off and on for the past 2 years, and enjoyed watching its development.
I’ve liked its sync model, and its Publish feature. But because Obsidian’s development seems to be prodded by a legion of plug-in developers who come and go, the feature set of the program lacks integrity; I latch-on to a plug-in only to find that it is either dropped because the developer got busy elsewhere, or the function gets absorbed into an Obsidian release with a reduced functionality.
The Obsidian Graph and link function is quite frictionless, but in my experience it creates the need for constant “gardening” to ensure that a multiplicity of links don’t overwhelm understanding.
All of this leaves room for a number of Obsidian gurus to step in and offer workshops in the effective use of Obsidian folder and tag structures. One can find oneself tinkering with the tool and never actually building anything.
I think that Tinderbox provides a more robust data structure with attributes, and a better analytical structure with its views, queries, and action code.
Obsidian does exist on multiple platforms, which can be a deciding factor; but once one get facile with Tinderbox Notes, Prototypes, Views, and action code, programs like Obsidian recede to a point that suits entry-level markdown enthusiasts.
All told, I get more work done more quickly when I start with Tinderbox than any other PKM tool.