I keep dual windows on laptop for rare occasions cuz I don't like dealing with passthrough for special USB cables that require their own drivers on VMs

Not on bare metal, for this reason

I do. I wanted to finish something there that I couldn't easily move to Linux. A DVD project using files scattered accross the system in DVDStyler. I didn't notice DVDStyler works on Linux.
Now I am basically keeping it due to sunk cost fallancy. It has lots of menus and videos, plus some of them I cut myself. But I don't even remember where I ended. There was also something about color limitation in menus I wanted to fix. I last shut it down during an update about 2-3 years ago.
But who knows, maybe later at some point...

But I could really use those extra 400GB. I only have 15GiB free right now...

I installed one when I made my first Linux PC last month in case I needed to use Windows for anything that wouldn’t work fine enough on Linux.

One month later and I still haven’t used it for anything. I think I may have underestimated how fleshed out the Linux ecosystem is these days.

I've been delaying moving my root arch patition from my HDD to overwrite my old windows install on my SSD for months.

I feel like the potential problems that that could cause aren't worth the better loading times from the SSD.