P.S. if Apple would offer more granular steps and pricing, it would probably lead to less revenue in the first place, but it would make many users like myself use iCloud as the only cloud service, due to the increased convenience for Apple ecosystem users, rather than spreading their data across others like OneDrive (1TB free space for MS Office users!) or Dropbox etc. Which would, in return, lead to more revenue and more customer loyalty, overall.
Therefore I strongly believe this would be a win-win for Apple AND users, which makes me wonder even more why they don't offer more granular plans.