If anyone looks inside th new DX8 -they will instantly see why the older designs are being dropped from new product sales
The wildfire advances in electronics have rendered the old approachs obsolete - not unusable but absolutely, obsolete!
FWIW - new electronics are far smaller - do far more -run on lower power (they have to ) and permit complete reprogramming as required.
As another example - pull apart any old 72 MHZ rx - it's full of discrete bits n pieces some which need final tweaking after assembly .
The 2.4 g stuf - - a chip or two - thats it.
JR will catch up -they MUST-to stay in the game
What was the latest stuf yesterday is old hat today- sure -it still works but you can't stay competitive selling equiment that has higher production costs -less modern approaches, etc..
Bluntly put - when Spektrum introduced the 2.4 equip -they caught all the others with their pants down and most are still nothing more than the old school stuff with 2.4 g output.