The flu only has a 0.1-0.05% mortality rate. The early symptoms of of it are flu-like but the severe respiratory symptoms that set in and make it difficult to breath are not like your typical flu, to my knowledge.
Maybe that's the tricky part that helps it spread. Having a cold isn't enough to stop most people from going out in public. In my experience among people I know in the US and Canada, having a mild cold isn't enough for people to stay home from work.
But while a covid-19 infection might really be just a cold to a large chunk of people who get it, it's unusually deadly to a non-trivial percentage of people as well.