Win32 would buffer keystrokes so that a sequence of commands wouldn't be lost even if the UI took long to respond (e.g. if a dialog took long to open), but that has mostly been lost in the era of web apps and other similar bullshit.
Modern web (and web-like) apps all too often don't even bother supporting keyboard for anything other than text field input. What I find especially infuriating are the dialog boxes where the only thing you have is a textbox and a button, and yet you cannot press Enter to submit the dialog once you finish typing - nope, you have to reach out for the mouse and click that button.
This is why I commonly have a trackpad in addition to a mouse when I use Windows. Literally, mouse on right, trackpad on left. It's much faster to use the trackpad for annoyances like these. I also find that trackpads are ten times better for scrolling.
