Sure, because search is actually a feature people want. I don’t want one drive or candy crush or telemetry data and all those are harder to turn off then changing search to DuckDuckGo on MacOS or iOS.
Mac OS does come with a fairly deep iCloud Drive integration, and iOS defaults to backing up photos and files then tries to upsell to a higher package when space runs out. It's only fairly recently that iOS shipped with a dedicated file manager, instead making you store any documents you have either in individual apps or on iCloud Drive.
To be fair, macOS asks once about the iCloud, and when told 'No', it respects the user and never asks again, and never puts anything iCloud related into users face.
