I recently bought a new computer (left the old one in my car by mistake, and the outdoor heat caused the plastic casing to expand) and moved all my old files over to the new one. Somehow, it ended up sticking a bunch of my files (Desktop, Documents, etc.) in my OneDrive (which was setup without any confirmation that I'd like to use it). I had to create a brand new profile that wasn't linked to a Microsoft account on my brand new computer and move everything over just to fix the issue.
Even setting up an account that isn't linked to Microsoft is tricky - particularly if it's the first account. You basically have to keep your PC offline throughout the entire setup, and even then as soon as you connect to the internet it'll start changing things.
O&OShutup is an essential piece of software to run, imo. You need to run it regularly also to catch the settings that get reverted with updates.
That's true, but getting a critical mass to do that with industrial software is like pulling teeth out your toenails. Most of the people writing it only know Windows.
The newer Rufus (USB ISO installation tool) let's you NATIVELY apply several mods to the Win10 installation, and one of them is to pre-create a user account that doesn't need to be linked to M$. My favorite feature.