Have you ever done any SERIOUS excel work without a mouse cursor? I mean proper, accounting-level Excel work... Well, let me tell you: pegging a million little cells with your finger is the most nerve-wrecking experience in the world!
The iPad "Pro" likes to portray itself as a laptop-grade alternative for professionals... Well, in that case it MUST provide laptop-grade tools, for Pete's sake! Both mouse support and a real file management system are a MUST to become a true laptop replacement.
A lot of people can’t see past their own nose. "Productivity" is often limited to programming, excel, and CAD, as if no other type of profession exists.
I would argue that an iPad can serve as an alternative to a laptop, rather than a replacement. There is this obsession that the iPad somehow has to able to replicate every aspect of a Mac, and that it is somehow overwhelmingly useless for the majority just because it can't do something that a minority of users might want to actually do on a computer.
The iPhone can do some of the tasks that a Mac can (and potentially costs even more than a Mac these days). Do people ever argue that the iPhone is crippled because it can't replace a PC?
My Apple Watch can do some of the tasks my iPhone can. Do people castigate the watch for not being able to replace a phone?
Likewise, my screwdriver isn't useless just because it can't be used to hammer in nails.
In the same vein, the iPad is designed to take on some of the tasks than a computer can do, while also allowing the user to perform some tasks better than they ever could on a conventional computer. Its purpose is to challenge users to rethink what a computer can do, not replace it entirely.
I mean, seriously, I work on excel and google sheet documents only intermittently, and I am perfectly content to wait till I am at home so I can get them done on my 5k iMac. That I can't work on spreadsheets as easily on my iPad doesn't obviate the fact that I am nevertheless still able to use it for a ton of other stuff (both productive and recreational) that don't really require cursor support.
And heck, if it's file management you want, dropbox + documents has solved this issue (for most part) since like...2013?