Here's the clearest/joke summary of the Sapling Theory.
"Ahem, The Sisters turned Zero Point Tree (uncontrollable/original form) into the Zero Point Orb (A controllable/Sapling.)"in order to control all of it without the hassle of controlling the branches. Geno erased The Imagined and Order's memories of forcing the transformation of the Zero Point Tree into a non-growable Sapling so he can invest in stonks and rule the omniverse with The Zero Point Orb. (The reason for The Loop and an obstacle for The Zero Point expansion), while simultaneously crushing his daughters' hopes and dreams.
Why The Zero Point was shown as an Orb was BECAUSE the reality branches and roots were invisible because of the rapid expansion of the universe was so fast.