Big issues and "grandiosity"
There is a long-running line in pop psychology that caring about the big issues is "grandiose." Whenever you hear that, you know that you are dealing with someone who does not know what they are talking about.
The big issues impact on everyone, including the people who are just trying to live their lives. If global warming gets worse, all sorts of people will suffer or die. If the Christian or Islamic narrative were to consummate, or their predictions of heaven or hell were to be true, then that would mean everyone as well. With half the people believing that we are living in Armageddon, and the world's best minds predicting a climatic catastrophe, this is very much the time for big issues.
And focusing on big issues at this time is the fully rational thing to do.