Meshtastic also struggles with high density and high traffic networks. Some modifications can be made to work better, but with the default settings it really grinds to a halt, and modifying the settings to be better suited requires some expertise and foresight. It works amazingly in off grid, relatively sparse networks, but it's got some major limitations.
The decision that every station is always a (delayed) router was a bad one. Also the old firmware was super chatty eating a lot of valuable ISM TX time.
They must clean up their role mess and switch to a "all clients are totally quiet - until they are set to a different mode for a reason"-strategy.
Yeah I always wonder with these mobile ever changing mesh networks: how do they prevent messages from aimlessly looping around the network? With all the mobile devices they're too dynamic to make routing tables and broadcasting everything leads to network saturation really quickly. You could give them a very short TTL but then the reliability will suffer a lot.