This is true in our solar system: our planets’ orbits are aligned to within 7° of the Sun’s spin. The main reason is that the gravitational forces between planets and stars are not uniform, so over time the alignment gradually drifts away from the star’s equator. As a result, planets form with slightly different orbital positions relative to their host stars. Over time, the differences become more pronounced (due to fasterthan-average tidal forces), leading to further drifting and finally divergence from perfect alignment.