SARS was at 3000 cases or so when we had 200 confirmed deaths. I remember the panic around a dude who spread the disease to literally like 200 people in Hong Kong and when the mortality rate appeared to climb from an early 6% to over 20%. And there were these apartment complexes in HK and Taiwan full of old people that were simply quarantineed and deprived of medical care. Not fun times...
Also we need to take into account that this is an older, more polluted, more urban, more wintry China then the one who faced SARS 17 years ago, and also one where there are far more people travelling around. All of this has impacted negatively in mortality rate, and contributed to spread it further.