[dan-robertson]

The parent comment may be talking only about the network or Citrix components in the critical path. You also have to wait to get keyboard input (often 10s to many 10s of ms) and for double-buffering or composition (you might get updates and render during frame T, flip buffers to reach the OS compositor for frame T+1, have the compositor take another frame to render that and send it to the screen for frame T+2, though this is a bad case for a compositor, you may be paying the double buffering or flu latency twice). And it can take a while for modern LCD screens to process the inputs (changes towards the bottom of the screen take about a frame longer to display) and to physically switch the pixels.

120ms end-to-end without Citrix would be quite achievable with many modern systems (older systems (and programs written for them) were often not powerful enough to do some of the things that add latency to modern systems). So if Citrix 120ms we already get up to your ‘not immediate’ number.

But I think you’re also wrong in that eg typing latency can be noticeable even if you don’t observe a pause between pressing a key and the character appearing. If I use google docs[1] for example, I feel like I am having to move my fingers through honey to type - the whole experience just feels sluggish.

[1] this is on a desktop. On the iPad app I had multiple-second key press-to-display latency when adding a suggestion in the middle of a medium-sized doc.