The piano and cello were made for each other. Every time I’ve ever heard these instruments speaking with each other (yes, that’s how I hear them), I am struck by their differences being so compatible. It’s as if the music gods said, “Ok, you occupy the tone space of strings being struck with a keyboard, and you can thread melodic lines in between those notes with a sound that seems inevitable.”
Of course, I could not neglect other instruments, especially the woodwinds which were becoming jealous and lonely as the piece developed. So they also get a say and everyone comes together towards the end.