Why do planets rotate around the sun in a fixed path (i.e., orbit) without bulging to any other planet？

I would like to correct this question in a few ways. Planets do not rotate around the sun. Planets rotate (spin in one place) around a planetary axis and revolve (move in a circle/ellipse) around the sun on an orbital path; however, I do understand the intent of the question.
If Earth and the Sun were the only two objects in our solar system, it is likely that Earth's orbit would remain static and keep a constant shape. But Earth and the Sun are not the only objects in our solar system, and other planets have mass; therefore, there is gravitational attraction between Earth and other objects. The greatest attraction (other than to the Sun) would be between Earth and the other planets. As Earth's gravity interacts with the gravity of the other planets, each orbit gradually shifts around its orientation. This doesn't happen quickly. It takes hundreds and even thousands of years. It's also possible that a passing neighbor star causes changes in planetary orbits, but this is something that would take a much longer time to possibly occur.
https://sciencing.com/planets-changed-positions-20126.html

https://www1.phys.vt.edu/~jhs/faq/astronomy.html