If you compare the number of serious cases to the number of total cases for different countries you'll get a 10x difference. Norway tests more thoroughly then the other countries, so it has a huge number of active cases. But from those only ~2% serious. There may be different reasons for such a discrepancy but I tend to agree with your conclusion that we have a lot of asymptomatic cases around, higher then estimated R0 and lower then estimated fatality.
Sincerely curious, how do you square this with the CFR in Italy at this time? That the initial impact to primarily elderly people and a low count of cases compared to a much larger undiagnosed quantity (still mostly undiagnosed cases) are creating a high death rate statistic? Or do you think some other factors are at work there?
I made a simple site to graph the daily increase figures. It only shows infections and deaths but from that you can see very different ratios for different countries.
You might try sorting the countries in your select input. They appear to be in some random order and I almost gave up looking for the country I was interested in.
I came to similar conclusion just looking at the openly available numbers: https://www.worldometers.info/coronavirus/#countries
If you compare the number of serious cases to the number of total cases for different countries you'll get a 10x difference. Norway tests more thoroughly then the other countries, so it has a huge number of active cases. But from those only ~2% serious. There may be different reasons for such a discrepancy but I tend to agree with your conclusion that we have a lot of asymptomatic cases around, higher then estimated R0 and lower then estimated fatality.