Do YOU know what you are talking about?
You certainly CAN create files on compatible programs on a Mac or PC and transfer that same compatible file on an iPad and vice versa.
Yes Wifi transfer is easier and faster, but can be done with most mobile drives and mobile flash drives.
You certainly can do with Apple's iWork apps on both iOS and Mac OS.
Other programs can do this such as other document or PDF creation apps on either iOS/PC/Mac.
Same with image/video editing.
I use both iMovie on iOS and Mac OS and can transfer data between the two NOT using Airdrop or iCloud for any of this, BTW! ( actually, for some tasks, I use DropBox OR there are specific data transfer apps that work across iOS, Mac OS or Windows)
I use Affinity Photo and Pixelmator and can, fairly easily without AirDrop, use files from created in iOS and continue to work on these either in Photoshop, Affinity Photo OR Pixelmator on my Mac and, again, vice versa.
Same with another painting program I use called ArtRage.
Can go back and forth ( I use either DropBox or another data sharing app called Instashare, because my older iMac does not have AirDrop capability) to swap drawing files between ArtRage for iOS OR Mac OS.
PDFs in iOS can easily be transferred to a Mac or PC to view either in Preview or another PDF app on Mac OS or Windows.
I can easily transfer photos/images back and forth from my Mac without iCloud or AirDrop.
There are other iOS Apps that make the doing pretty easy and painless.
Other examples AutoDesk SketchBook on iOS/Mac OS
MediBang Paint for iOS/Mac OS/Windows
Notability for both iOS/Mac OS ( Not sure if this has a Windows version or not)
So, you argument doesn't hold up all that well!
I have both an large iPad Pro and late 2009, 27 inch iMac!
I even have apps that pair with my iPad and my iMac, so I don't even have to work, directly at my iMac, if I don't want to at that momemt!
I think you get my point.
Still need Wifi to do much of this without relying on mobile storage drives, though.
But still very possible to do with mobile wireless hard drives/flash drives.
You don't need iCloud or AirDrop to transfer files back and forth from iPad to computer and vice versa.
That is just one method to get data back and forth from mobile device to a more powerful computer.