You are all right.
There are already solutions. Triple play,SY200 and even with the kemper right now synth leads are quite possible with our KPA.
Thing is..
These solutions are imo not really "fire and forget".
The triple play has a very good tracking but still needs the midi tool to be mounted on the guitar. This sucks.
The SY-200 is a great tool but for me it sounds often to "digital" and sits to often not well enough in the mix.
Some warm,fat "monophonic"moog lead for start and later other additions would be the next step which should be possible with "more cpu" in the near future and then we will see what is possible with upgrades in the coming years. This is how I would love to see a KPA2.