I am curious if there have been studies on how much the slowness/delayed response of the device improves the attention span. (Since the distraction urge cannot be instantly satisfied)

Anecdotally, I find it very easy to get distracted when clicking on app takes fewer than a few seconds to start. When I test-drove the PinePhone, I felt I was much less distracted because bringing up the browser takes good 5-10 seconds, so I would only do that with a specific goal in mind.