I've been in this situation many times too, but I have to say it feels like a weakness. When a single person works on a problem I see improvements being left on the table compared to when two people effectively collaborate. I've experienced this in a wide range of skill/experience levels so I don't think that is the problem.
That said, I don't know how to change the situation if you have devs with skillsets that don't seem to overlap much, which seems inevitable for some companies
That said, I don't know how to change the situation if you have devs with skillsets that don't seem to overlap much, which seems inevitable for some companies