The main reason your pothos is getting leggy is insufficient light. Pothos needs bright indirect sunlight to thrive. If it’s growing in a shaded location, the plant will start sending out long vines in search of a better light source.
Giving your pothos too much fertilizer can also give it a leggy look. Essentially, this triggers an unnaturally fast growth sprout.
All pothos species are natural climbers. In the wild, they use their aerial roots to attach themselves to tree trunks and climb towards the canopy, where they have access to more light.