Full screen of content within 64 ms.
Sure, I definitely expect a checkbox to do something in < 100ms. Show that its state changed and at the very least show me some kind of loading icon so I know something is happening.
But a full screen of content in 64 ms? Unreasonable, and really a completely undefined unit of measure (what is/how big is a "screen" and how much content can fit within? How do you measure audio or video content? What happens when I'm working with vector graphics that can't possibly render in 64 ms?)
There were plenty of applications in the 80s that could not render a full screen in that timeframe. That did not stop those applications from being useful.
(And I honestly think a DOS directory listing can take longer than 64ms to fill the screen)