It’s probably the well-known disconnect between the speed of onset of a disaster and the perceived significance. Climate change is a slow-moving juggernaut and not always obviously connected to day-to-day life, so it takes a back seat to the problems that people face right now.

Of course, there’s also Maslow’s Hierarchy of Needs - if one is struggling with the day-to-day necessities, they are hardly going to have the bandwidth to focus on more general issues (and as an aside, I have to wonder if this is also part of the political strategy in the US - you can’t participate in activism if you’re struggling to keep a roof over your head or food on the table each day).