> The AV stuff is huge. It’s always why windows Windows 8 era PCs were maybe the most brutally slow.

IIRC Win8's also the first Windows I found unusable on spinning rust. Part of it may have been AV, but things like opening the start menu had significantly worse delays there than on a flash disk. It seems like they'd simply disregarded all development/design discipline about disk I/O, across the OS.

... which, you keep doing that everywhere, lots of devs making lazy choices to just grab this from disk here or just write a little data synchronously there, and it'll add up to non-negligible delay, even on a flash disk. And it'll make an HDD craaaawl. Which is exactly what happened.