No hard rule here between the two imo, case by case basis depending on your body-shape, shoes and the pants in question. Tfunks cutoffs in that recent hillbomb post look ridiculous, shitty raggedy too short pissflaps blowing in the wind.
I'd say hem, if you can. Over lockdown I borrowed my flatmate's sewing machine and started hemming the more ridiculously long pants, and cut and hemmed a few into jorts. Jorts are great for skating in, your feet aren't weighed down by denim, but you feel more protected skidding on your ass.
Sometimes cutting them shorter means the leg openings are now too wide, and need to be tapered again, which is easy enough, just do it before you hem.