Well maybe not slower than anything from the 9x era, but it is definitely slower than it was on Vista for example.

Also e.g. the "Whiteboard" program which replaced the older "Sketchpad" program in Windows 10 tablets. The Sketchpad opened even before I released the button on the pen, while the Whiteboard crap just takes forever to open, then takes forever to "login to Microsoft account", then takes forever to load anything...