We do have different ideas of Pro users. I don't know any who use iCloud, which has reliability issues and is inside a walled garden. I'm as big an Apple fan as anyone, but iCloud is a joke.
I've even asked Genius Bar employees exactly how people are supposed to use the iCloud photo backup. They've admitted that they don't really know what to make of the system, which is not transparent with regard to what photos have been downloaded where. It is difficult for the average user to understand how the file-shrinking system works with photos, and which photos exist only in the cloud versus on their machines.
It's an iPhone backup, of course it's a "walled garden". It works really well, maybe you haven't used it in years. I can literally throw my phone into the ocean, walk into an Apple Store and within a short time be right back to where I was. About the only things that get lost are Face ID and Apple Pay, which don't last through any backup because the Secure Element is one way.
Not all iPhone backups are walled gardens. I can back up to my computer, and back that up to various local/cloud drives. I don't want another thing that's wedded to an ecosystem that I might leave at some point.
Also, if I'm already paying for generic cloud storage services, why should I pay for Apple-specific cloud services, at a more expensive price per GB?
I've even asked Genius Bar employees exactly how people are supposed to use the iCloud photo backup. They've admitted that they don't really know what to make of the system, which is not transparent with regard to what photos have been downloaded where. It is difficult for the average user to understand how the file-shrinking system works with photos, and which photos exist only in the cloud versus on their machines.