This is interesting. I have had the very strong internal voice for as long as I can remember. I also have 'imaginary friends' (for want of a better way of defining them) which I have had since I was a small child. They have grown up with me, and I would be a bit lost without them.
The internal voice, does occasionally become didactic, and may repeat criticisms that I have received in the past, even taking on the voice of the person who criticised or insulted me. Yet, I know the voices are not real.
All this, I regard as normal, and as a way of dealing with the world e.g. I can act as counsellor or counselled via the 'imaginary friends', and, when I am alone, I speak out loud to myself because it helps me sort out my thoughts or get through a task systematically. I would be a much less complete person without my internal world, to be honest.
My eldest son and husband have both experienced psychotic episodes, and their experiences were qualitatively different. They believed that people were saying things to them, that people were plotting against them, that things had happened, that were obviously not real. My son still hears voices, but he can cope with them. Some people in his 'hearing voices' support group say the 'voices' have become kinder to them. My son has yet to experience this.
My youngest son, often had terrible graphic images and a hyper-critical internal voice. This seems to be a manifestation of his OCD and other anxiety disorders. He knows they are not real, but they can upset him and stop him in his tracks. He also has an eating disorder and has an 'ED internal voice' which is not helpful to him at all.
So, in my experience, the human mind is fantastically complex. Our thoughts and imagination can be helpful and a huge resource for reflection and getting through daily life.
Yet, there can be times when, perhaps as a result of mental illness, we misinterpret or lose touch with reality, and at those times, we will need professional support.
There are other times when our mind's ability to imagine, play or replay scenarios, including voices, becomes unpleasant and unhelpful, even though we do not lose touch with reality. At those times, we may also need help.
It seems that your internal voices and thoughts are mostly helpful, but there are times when the boundary between reality and imagination become blurred. This is just my opinion, and it would be more helpful if you sought professional advice (especially if you feel the voices etc are affecting your life negatively).
Others have mentioned neurodivergence. My eldest son and husband are both neurodivergent. My youngest son is in the process of assessment, and I am NT (as far as I know).