Nowadays Windows is filled with adware and is fairly slow, but it wasn’t always like this. Was there a particular time where a change occurred?
Windows 2000 was the peak - rock solid with no visual fluff. XP was 2000 with a childish skin on it and it’s all downhill from there.
I remember all the nicknames from when XP came out. I don’t remember which was more common; disco windows, or teletubby windows.