Successfully built a treehouse with my kids and I'm still shocked it didn't collapse

Got permission from the wife (barely) to let my 9yo and 11yo help build a treehouse in our oak tree. We spent last Saturday gathering supplies and planning it out - honestly spent more time on safety planning than actual building, which I'm sure is boring but whatever. Used a kit from Backyard Adventures and ngl it was actually pretty straightforward. The kids did like 40% of the actual work and they were SO proud when we finished. They've been out there every day since. Best $800 I've spent in a while. 10/10 would recommend if you have a suitable tree.