@Denny - Due respect, not much confusion here (I hope! ). You are correct in that IOS can (in a limited way) deal with thousands of files, but fully using the files, as described below, can be slow and tedious. IOS tends to be app-centric. Files are (usually) created, stored, organized or managed through certain apps. MacOS is (or can be) file-centric. Through the Finder or Finder-substitute apps you can live, breathe, even swim directly in the files, if you want. You can, using two or more windows on a large-enough screen or multiple screens, see your entire file organization structure (top level folders) simultaneously with at least one folder/subfolder/sub-subfolder branch displayed. And with that display duplicated showing another folder/subfolder/sub-subfolder branch. You are then free to peruse and wade through the files database in an unrestricted way.
It’s quite easy in iOS to place files into the database - I do that all the time. Example: Scan (using Scanbot or similar app) a receipt, automatically saved into a Dropbox folder. Done. I do that all the time. The iPad is not even needed - the iPhone works fine.
Dealing with the files - retrieving, combining, searching, re-organizing, placing into files within other apps (Notes, Pages, Numbers, Excel) is much easier and faster with macOS. One example: I have 30+ years of investment and brokerage statements saved as PDF files. The paper documents, along with boxes and boxes of others, were scanned to PDF files and discarded long ago. After redeeming shares of a stock or mutual fund, I need to calculate the cost basis after years of reinvested dividends in a stock DRIP plan or reinvested distributions in a mutual fund. That requires at least two looks through the files. A quick look to discern the pattern of dividends or distributions (monthly, quarterly, just certain months, or yearly) for each security, then a detailed look through the appropriate documents to copy the figures over to a new spreadsheet. Almost forgot - a preliminary look-through is needed to account for mergers of investment firms/brokerages and transfers of securities from one firm or account to another.
Yes, I know it’s easier now that investment firms keep track of cost basis for you. But they didn’t in past years, and even now cost basis tracking may not survive transfers of securities to new accounts or to new investment firms or brokerages. And yes, I have cited a “special case”. But there are many “special cases” requiring meandering, unstructured looks through a database.
This task is straightforward using macOS Finder with multiple windows, maybe even multiple monitors. It’s even easier than going through dozens of boxes of paper documents. I shudder to think of doing this - or similarly involved tasks - in iOS.
You could, with perfect foresight or clairvoyance, organize your data in advance in such way that would make iOS adequate for later use. In 1981 when I started investing (or making home improvements for which similar cost basis records might be needed), I was not perfect and didn’t have such clairvoyance. Nor in 2010, when I began my big “paperless” project to de-clutter my home and my life. I just saved all of the data in a very big file/folder structure to be accessed later.
@Denny mentioned projects. “Projects” is irrelevant concept for me. I had no idea what my “project” for particular documents would be in 1981, 2010, or even now. What I do know is that some fraction of the documents I’m saving in digital form will be useful later, but perhaps in an unforeseeable way. No clairvoyance required . That and perfection are in short supply in my universe.
Did I mention direct access to an attached disk drive? That’s a must. And backup. All of my macOS files are backed up in multiple ways, twice to locally-attached disk drives (one using the standard macOS Time Machine) and one off-site cloud backup (Backblaze). I suppose iOS files are synced to iCloud, but is this true backup?
Over the last few years iCloud has improved, but I still don’t trust it as much as Dropbox for sync. There was a time period a few years ago when iCloud sync mangled many users’ 1Password files. This was an acknowledged, system-wide problem at Apple. That’s when I started using Dropbox for my 1Password vault sync, which has been rock-sold since.
I love my iPad Pro - use it every day. But it won’t replace my iMac for my type of file handling without major structural change to IOS.