While your sentiment is in the right place, trees are not a one size fits all solution. There's a variety of ecosystems on this planet, and not all are densely packed forest. Instead of everybody just planting a tree, it's important to think about what kind of tree and if a tree would be beneficial at all. Sometimes planting a native grass would be a lot more beneficial in a specific context.

One other thing is that the places where pine beetles are the most destructive are monocrop pine forests. If you have diversity in your forests, it makes them more resillent to this kind of thing.

It should be every human's role to learn about how their local ecosystem works and how to exist within it in a reciprocal way.