@Nocturnalhaven22 you can build your own treehouse the way you want it if you haven't already had a go at it.
I use walls first and place a first floor as a blank square, then another room on the second floor. Then I delete the first floor and add wooden columns to support the second floor structure that will be my treehouse. I add ladders to climb up to it.
I use the tree stump seats from the Outdoor Retreat pack or from the base game, place one between the supporting columns and enlarge to look like a large tree stump with the treehouse sitting on it. Then I can customise the treehouse however I want. Little Campers is a good kit for that but it's not essential. I add a load of fairy lights and it's done. I place large trees around the outside.
It makes a cool main house too if built on a bigger scale. I've built a treetop house in Sulani this way.