With 1 in 30 chance of death can somebody help me understand why this had to be a manned mission?

It was essentially a dress rehearsal for next year's mission, which will result in an actual moonwalk. And then in 2028 we will go back for a second moonwalk and foundation delivery to start building an actual moon base. Artemis is a really cool and systematic set of missions that ultimately will result in a permanent human presence on the moon.