That is because your misinterpreting the data. Those higher death rates were from only testing the more I'll people. Your link doesn't support your point.
What it actually means is that many more people were infected than were reported earlier on. Now they are reporting more accurate numbers. The death rate is always 1% to 2%.
If you see a higher reported deaths rate then that tells you how many unreported cases there likely was. Not that it is less deadly now.
