Especially when there are three different versions, and each has a different team, and they all can work together at the same time. Crazy amount of tech supporting it that breaks a humans context let alone a models context.
Ever letter is it's own object and they stitch it into the visual view. When you type one letter is turns a single word into multiple objects all versioned objects.
Can't imagine all the crazy race condition protections baked into that.
These guys puposely obscure controls and understanding of these products 100% to prevent you doing a port.
Just go open a microsoft word doc in the browser and look at the dom.
Despair! Horror!