I've never really been a massive fan of box breathing tbh, but it's really whatever works for the individual. If you're slightly obsessive focusing solely on your breathing can lead to anxiety over having to manually breath and it doesn't do much to quieten an overly busy mind.
It seems obvious to say that people would get a lot more out of taking 5 / 10 / 30 mins for proper meditation / guided relaxation, especially if you want to actually get the benefits of deep breathing. I don't really know any mental health practitioners who wouldn't recommend (prescribe) it when dealing with anxiety, even the CBT textbook followers.
Mindfulness of breath is a corner stone of many mediation / mindfulness / relaxation techniques. In Buddhism the term for the permanent self or soul is Ātman, which also translates as essence, or breath. Buddha himself recommended breath meditation, saying it was something he discovered by accident as a child & going back to it as an adult brought him more enlightenment than all the religious studying he had done to that point.
If you need an alternative quick mindfulness technique I quite like this one. Close your eyes, then find 3 to 5 separate sounds you can hear. Then find 3/5 things you can physically feel. It's quite good for taking your out of your head, placing you back in the physical world & often at least one of the things will be related to breath.