
2 things could be happening. A: the roots have outgrown it and it does need repotting. (Most likely) B: They just wanted to grow that way for some reason. (Possible but less likely) Have you ever taken a plant out of a pot before to check the roots and if not do you believe you know how? The real check would be to see how densely the roots have grown but honestly at this point and with how resilient pothos are I see very little harm that could come from repotting.