Alas, the POG and the H9 are different animals. The POG can do polyphonic pitch shiftings, and little else. The H9 is not great at polyphonic pitch shifting but it is great at so many other things.
We understand that you want one pedal to rule them all, but this is not always possible. Horses and courses.
I am amazed at the demands made of the H9 versus the demands made of any other guitar pedal. The only thing more amazing is Eventide has managed to cater to some of those demands in the form of software updates. I do not know of any other company who is actively adding requested features (not fixing problems) to their guitar pedals 4 years after they were purchased without needing to touch the hardware? What pedal would you replace your H9 with?
“One pedal to rule them all” is impossible. “One pedal to get the job done, and get the job done well” is within the realm of possibility, This depends largely on the job that needs to be done and whether H9 users want such a product in the first place. I trust Eventide knows what they are doing and if they don’t, they are figuring it out. I also think they would like people to continue wishing for more H9 wishes.