Our brain main role is not thinking (that's more like a side-effect) but keeping us alive/safe at lowest energy cost. Changes A) are risky B) require energy to adapt. For our hunter-gatherer ancestors, doing things the way that their priors did was pretty good bet usually.
I recommend book "Seven and a Half Lessons About the Brain" by Lisa Feldman Barrett where she talks a bit more about that.
On the other hand, trees cool down the area so having lot of them should lead to fewer heat-strokes. Last week we hit 95F in my area and I wouldn't be able to walk my dog if not for the trees.
Is not an easy decision. Politicians can be sued if a branch falls over somebody, but can get rid easily of the ten thousands of kills a year by contamination on air and water. Of course somebody being crushed by a tree is a real tragedy, but if the same people would have a heart attack because nitrogen emissions are out of the charts, or they get ill by asthma and can't work, would not reach the news.
An interesting question is: Have people trees because is rich, or they are richer because they had trees? (and this will save a lot of money each year on energy bills, food and even psychologists). Trees are a tool to fight poverty. The problem is how to made the poor people respect them.
You haven't been around teenagers, or even humans in general much, huh?
Teaching another person, even an eager one, how to change their behaviour and mental patterns concerning validation and FOMO is a really hard task. It's not knowledge like math or something that you can just pass onto them. It can take months or even years even for pros (psychitrists etc.) to do that. Combine that with the fact that teenagers brains are wired differently (their need to fit it is greater than that of an adult) and their "natural resistance" to adults' teaching and it becomes almost impossible task.
I recommend book "Seven and a Half Lessons About the Brain" by Lisa Feldman Barrett where she talks a bit more about that.