"Ok then, you can have Matt 16:28 or Luke 9:27, same deal, same thing described, the Kingdom did come, just not on earth yet, as in heaven."
No, the "Kingdom" did not come. You need to re-examine this interpretation of yours.
Read the context in which those verses appear.
You cannot exclude that Jesus was preparing his disciples for his death ... as per "It is written that the Son of Man must ..."
He was also preparing them for his resurrection and second coming. Imminent because it would occur in the lifetime of some of those present.
Unfortunately the writers of the gospels made a complete mish mash of this story and spent too much effort in incorporating the age old promised Jewish Messiah "rescue mission" into the narrative. Jesus as Messiah would return with Angels, trumpets, free McDonalds burgers and Medicare for all, to right every wrong and get the Tax Dept. off my back.
(Disclaimer ... References to Tax Dept. is dramatic fiction and bears no resemblance to my personal continuing tax free status.)
The gospel writers, ever ready to proclaim to the Jews that Jesus was their Messiah, described this coming with pomp and fireworks and Angels and trumpets and just judgment and gnashing of teeth, as the coming of the Kingdom of God. However, that's not the same Kingdom of God that is referred to elsewhere eg with the Pharisees. It's also not the sending of the Comforter.
These refer to different things.
Some early Christians thought Jesus was the promised Messiah and would return to fulfill their desires.
Others understood it as an inner journey.
The popular Biblical interpretations are fanciful.
