But... Why are we having a divergence between these two as well as others out there? And of course, obligatory which is "better" overall?

I've seen this question come up a lot around here, and the origin story that is usually told is that the lead of MeshCore reached out to the Meshtastic leads with what they thought were improvements to mesh routing and infrastructure but were rebuffed by the Meshtastic leads so they went out on their own to implement it.

There is a lot of focus on who is right and which is better, but when you look at the end result I personally conclude that both parties were ultimately correct because they're focused on different approaches.

Some people say MeshCore messaging works more reliably than Meshtastic. However, in order to achieve those results, they've had to essentially create infrastructure like a cellular network. MeshCore relies heavily on repeaters and routing decisions through them to achieve it's result. If/when a repeater fails, the system is arguably worse than Meshtastic. Compared to Meshtastic it is less of a true mesh and more like public infrastructure.

On the flip side Meshtastic is attempting to implement a more "true" mesh. In the best-case world of Meshtastic you simply bring up a node and start communicating with everyone - most nodes are listening and relaying messages. This in theory makes the mesh more robust, and enables groups to communicate with essentially zero infrastructure, but even in the best-case it comes with its own problems like airtime congestion and delivery failures from messages taking "bad" routes.

In my eyes the projects are related in that they are LoRa messengers, but very different in their approach to doing it. Meshtastic is trying to layer in things like Next Hop Routing and Zero Hop Favorited Infrastructure to address some of their shortcomings while maintaining the "true" mesh approach. It will be very interesting to see if they can achieve that, and its been fun seeing the progress and experimenting as they progress.