Boot Camp fails when loading Windows 10 ISO on MBP 2016 macOS 10.13.6 High Sierra

This was solved by simply upgrading macOS to something later, in this case to Big Sur

Apparently, the App Store will only automatically update macOS to High Sierra. After that, one has to manually download a newer versions of macOS so that its software updates will appear in System Preferences instead of the App Store.

Running BCA a second time directly after it fails, gives a "The startup disk cannot be partitioned or restored to a single partition." error. To resolve this:

1. Open the Disk Utilities app.
2. Select the Macintosh HD partition (or equivalent) in the sidebar.
3. Click the Partition button in the toolbar.
4. Click the 'Partition' button in the pop-up window.
5. Select the * sliver in the pie chart, which corresponds to the failed boot partition (here, OSXRESERVED).
6. Click the '–' button below the pie chart.
7. Click the BOOTCAMP sliver in the pie chart.
8. Click the '–' button below the pie chart.
9. Click the 'Apply' button, which opens a window confirming which partitions to remove.
10. Click the 'Partition' button. Disk Utility should remove the failed partitions. (If it doesn't, try rebooting. Sometimes, Disk Utility is silly like that.)

Issue:

Boot Camp Assistant (BCA) fails at (or just after) the "Copying Windows files..." task in the installer...

...giving a a "Boot Camp Installation Failed" error saying "An error occurred while copying the Windows Installation files"...

... while a pop-up noting that "Boot Camp Assistant is trying to add a new helper tool" appears.

By the time the helper tool pop-up appears, the job has already failed. Approving the tool does not allow BCA to finish, nor does it help in subsequent runs.

Some articles and discussions, around 2017-2018, noted that the boot partition is formatted as FAT32 and contains a file larger than 4GB. However, this was supposedly resolved according to this article whose author had previously created a workaround for the issue. They state that BCA was updated to use ExFAT.

At the same time, as of Feb 2022, the boot partition (in High Sierra) still reports using FAT32.

A YouTuber created a walkthrough that reformats the boot partition to ExFAT while adding manually-downloaded Windows Support Software. Upon following the instructions, mounting the BOOTCAMP partition, and rebooting the computer into Windows, I end up at a low-res Windows Setup screen (like the screenshot below but much smaller because of the natively high res of the MBP). However neither the MBP's built-in keyboard nor TrackPad work, and I can't get past this screen.