If a company is able to leverage dominance in one market to catapult to the top of another market, then that company was too large and powerful in its original market.

Probably the canonical example of this is Amazon. They started as an online bookseller, then expanded to other products as other booksellers closed up shop all over the country. They added their marketplace and then leveraged all those things to market their cloud platform. Even Microsoft and Google have not been able to dislodge Amazon's cloud dominance.

Amazon is currently in the process of trying to dislodge UPS / FedEx / RPS / DHL from their places in shipping and delivery. Since they probably provide the bulk of the products that these other companies ship, the effort is likely to be successful unless government intervenes.

I'd favor dividing the cloud platform from the e-commerce business and most of the logistics (warehouses and shipping) business from both of the others.