[2020] Benefits of cutting branches?

I didn't realize you could do it until yesterday. I've seen some advices on cutting branches so I'm trying to find the correct answer for 9.0.5. Is it useful to trim the tree before felling? Does the tree die? It seems when I cut the branches beforehand I don't get nearly as much pulp or seeds. Does it help prevent trample and killing plants nearby? I noticed on my map that most of the "trample sum" is in places where I cut a tree down.