I remember Scott Manley asked someone important on the dev team of ksp2 how they approached the 2 body problem. They guy gave a vague answer that they had solved it. If that were true they would have a Nobel Prize but they don't. So then and there I decided that KSP2 will not get my money. Which sucks because I have put a little over 2000 hours into KSP1.
I don't think that was the way he portrayed it. He made it seem like they really solved the 2 body problem. Scott Manley even made a comment about how grand that was. I really wish I could find the video to better show what I mean.
Funnily enough, there is an n-body mod for ksp1, which makes interplanet interactions more realistic (in fact, the mod has to slightly change the default system to stop the moons of Jool from slingshotting each other out) and allows advanced maneuvers like ballistic capture and lagrange points
And as someone who couldn't even land on the Mun without crashing, I downloaded that mod and unsurprisingly found things even harder since it disables the standard maneuvers.