It was always slow on contemporary hardware. On affordable PCs Win 3.1 was so slow you could see it redrawing windows and menus. Win 95 was so resource hungry, people wrote songs about it (https://www.youtube.com/watch?v=DOwQKWiRJAA). XP seemed fast only at the end of its very long life, due to Longhorn project failing and delaying its famously shitty successor.
It wasn't just Windows. Classic MacOS for most of its life could not drag windows with their contents in real time. Mac OS X was a slideshow before 10.4, and Macs kept frequently beachballing until they got SSDs.