All those examples are both quick and obvious dangers
Nuclear radiation is neither quick nor obvious. We also cannot assume
even a higher technological culture will know how to get rid of or
change radioactive material into something harmless.
We owe it to the future, whatever state it may be in, to at least make
the attempt to warn them about the messes we have made. The
project has other benefits to it as well, such as learning how to
preserve information and knowledge for future generations.
And I am for nuclear energy to power our society and and spaceships, FYI.