Exactly - we all don't have to be doing that all the time. And MrBeast does not choose random people or even poor people for these challenges, he chooses only his own subscribers - people who are already interested in this content and presumably watch it regularly and are delighted to be in one of the videos.

For the exact same reason why we teach little kids to throw their litter in the garbage bin instead of the ground, and hope that it will stick into adulthood: a range of values and ideas that display a due sense of caring and compassion.

Everyone should, but he seems to be particularly in a position to do so.