A little while ago I ran Windows XP in a VM, inside Windows 10.
I noted that when I pressed the start key, the start menu opened.
I noted that when I pressed Win+E, an explorer window opened.
Fully rendered. After a single video frame.
On Windows 10, the same thing happens, only several hundred milliseconds later, and then you get to enjoy watching the UI elements get painted in one at a time.
Twenty years of progress.
Windows Explorer taking multiple seconds to load and often a bright flash of a white background during the load was exactly what pushed me over the edge to Linux.
Presumably that's to keep hardware sales up, e-waste be damned. You won't notice it taking 8 times longer when you have 8 times as many cores, or whatever.
Few years back I was complaining to a coworker: "I just love opening Teams and watching it draw its subwindows in one by one, like a Windows 1.0 app on an 8086."
First flat design, now sluggish window redraws... Windows is getting retro hipster. Will 26H2 take away overlapping windows?
I'm forced to use the Microsoft ecosystem at work and the sluggishness of it is a major source of procrastination. I find myself putting off small tasks forever, because waiting for word files to open, browsing folder structures in Teams, etc. are all mildly painful experiences. I suspect a lot of people do this, and maybe all of them don't even realize why they are doing this. The effect of sluggish user interfaces on overall productivity is probably well underestimated.
The same goes to some extent to anything with a web interface, for example Databricks.