A capable person can still choose collaboration.

Collaboration is often read as something people do when they cannot manage alone, which makes capable people reluctant to work with others in case it looks like need. But choosing to work with someone when you did not have to is a different act entirely. It usually produces a better result and it is available to you precisely because you are capable.

Think of something you are handling solo purely because you can. Ask whether bringing someone in would make it better rather than merely easier. If it would, do it, and be clear with yourself that this is preference rather than deficiency.