If you believe in any implementation of e2ee made by apple i wish you good luck in life, cuz u will need it with your naivety.

Apple makes a shitload of money from the devices and ecosystem that have access to their cloud storage, they don’t have the same incentive to use the data itself for profit. In fact, keeping the data as private as they can is a selling point for the devices and ecosystem they make bank from. Dropbox doesn’t have that.