Since we talk so much about personality choice and responsibly in the US: it's their decision to take that risk, not yours.
While the death rate was low, it was way, way, way higher than usual cause of death at this age.
Also think about it in another way: a disease which impairs 1 out of 5000 people is not considered "rare" by any health authorities. For people 20 to 40, the death rate of covid was between 1/500 and 1/1000.
And i have another point for more economically-minded people: people from age 0 to 25 cost money to society. People 25 to 55 are net positives, as they contribute much to the economy: they consume a lot, they build a lot, they have energy for associative tasks and for child rearing. They are perhaps the most productive members of society on an island. Then consider people 55+. They are less productive, on an island, but sometime they have so much experience that loosing one without warning can set a company or some research back a couple of year. Also, they consume a lot, so loosing a lot of this population suddenly would destroy any economy riding on internal consumption.
The last argument is probably why policymakers of countries not know to care much about their workers still reacted quite fast (maybe overreacted: i don't think so, but i understand pleople saying that).
They are a public health menace, and should be quarantined until they are no longer infectious.