Chip Kelly is an interesting character. He had a lot of success early in his career, as an offensive coordinator at New Hampshire then at Oregon before becoming HC at Oregon. He even made a splash when he first got to the NFL, but after his first couple of years in Philly, his career has been on a slight decline. There was the disastrous year with the 49ers followed by some mediocre years at UCLA.
His team at the University of New Hampshire set all kinds of offensive records, and his Oregon teams were pretty impressive, too. But those teams relied on the running QB, and unless you have Lamar Jackson, that won't really fly in the NFL.
He's creative and smart, and maybe he can come up with something new. But he's 60 years old, and even though that's not old, I wonder if he's past the point where he's coming up with new schemes.