Collecting stats on the progression from clinical presentation of the patient all the way to death seems to me a bit tedious, since death is altogether somewhat rare and when it does occur it's a lot of factors playing together.
But the following article really put the fear of god in me, as it's the first source I've discovered that gives you an idea of the rate at which patients progress from clinical presentation to "going severe". Here a doctor gives details on the criteria they use for separating patients which are not altogether that restrictive, basically just saying that the patient must test positive or have been in contact with someone who did: "We have an observation unit in the hospital, and we have been admitting patients that had tested positive or are presumptive positive; these are patients that had been in contact with people who were positive." Elsewhere in the article there is mention of the rate at which these patients progress to going severe: "About a third have ended up on ventilators."
https://www.propublica.org/article/a-medical-worker-describe...
My guess is that the clinical point of view around Covid-19 is currently probably a well-kept secret among clinicians and that Ioannidis probably doesn't have access to that kind of "inside information".