Because of the split. But your right, meshtastic does have dumb routing. And I haven't used meshcore, but I probably won't now until the dust settles on this for a while.
I would like to disagree with you here that perfect is the enemy of good for mesh networking. It's not that meshtastic is good, it's not. But the barrier to get to good is far harder than the offerings. There are three primary issues.
1. Lora can typically only receive and listen on one channel at a time. This prevents listening and transmitting on anything but the one channel. If you could have multiple channels, the incidence of radios stomping on each others signals would go down.
2. The FCC limits 900MHz unlicensed operators to 1W of effective radiated power, and Lora really isn't optimized to make that 1W go as far as possible.
3. A good mesh network will have reliable delivery and routing. Meshtastic is more "spray and pray".
FT8 works very well as a digital modulation, and it solves the first two, but it doesn't solve #3 even though it makes it so much easier to design a solution for #3.
For a real life example: FT8 on 5W of RF power can often get my signal from North America to South America, Canada, Australia, Japan, etc.
If you listen to 14.074MHz, that's the channel that primarily is used for FT8 on the 20 meter band. Pick a random Web SDR from this list [0] and tune to that frequency and set it to USB (Upper Side Band). The channel width is only 3Khz, but each one of those squiggly lines is one station transmitting a signal.
I was getting very good signals with this one [1].
[0] http://kiwisdr.com/public/
[1] http://21959.proxy2.kiwisdr.com:8073/
