In particular the F-47 is expected to act as a forward control node for drones. We're probably decades away from having AI software that can autonomously execute any type of complex mission. So that means there's a critical need for a crewed aircraft survivable enough to get close to the target, even if it doesn't have to directly employ weapons itself.
A few really good planes and a lot of low-end drones is probably what we'll have in a few decades.