Same with "bad trips" (on psychedelics). The people saying there are no bad trips are pointing to a good truth that difficult trips can bring a lot of growth and healing if you accept and explore them and what's causing that feeling, but there are also truly bad trips with no upside, where in every way it would be better for it to not have happened. They're super rare, but it's definitely wise to have a trusted friend or therapist present, especially the first time you do them or do a big dose