No, it's not a "significant risk". It's basically the flu to the young. The IFR for that age range in good health is basically in the ballpark of the flu, which is a rounding error.
Normally being wrong on the internet is just ignorable, this isn't. At its best, this is 10x more deadly that the flu (more so for young people because almost no one dies of flu while young). You can dismiss that if you like, most people are right to not.
https://www.independent.co.uk/news/health/coronavirus-younge...
We simply do not know yet whether it is a good idea to infect everyone.
Why is everyone here a medical expert?