What you're saying is all true. It's also true that that 50% mortality rate is almost certainly also heavily skewed because of a lack of testing, meaning that fatal cases are much more likely to be tested for the specific variant responsible. This is even more probable given the overwhelming majority of cases and deaths over the past 20 years have occurred in developing nations, in the same way the overwhelming majority of all flu deaths occur in developing nations. It remains to be seen what the actual case fatality rate is, which due to the rarity of infection we won't be able to determine unless it starts passing between humans.

Over 700,000 people die every year from common variants of the flu, where 463 people total have died over the past 20 years from H5N1. We should always be working to reduce flu mortality, and this H5N1 outbreak is certainly something to watch closely and be prepared for potentialities, but also the sky is not falling.