I've seen the same kind of visualization made from different sources before showing the same point. There is really nothing shocking or unbelievable in the picture?

It's fine to be sceptical because it is an estimate. However it is a qualified estimate. Read more from the source: https://www.prb.org/articles/how-many-people-have-ever-lived-on-earth/

If you have a better way of estimating the figure, I'm sure they would be all ears.

I do remember reading school books and science articles 30-40 years ago and the estimates then were different, but that's just how science works.

Again it's fine to be sceptical, but unless you can provide an alternative figure with better documentation, I really don't understand why you're encouraging people to be sceptical.

It's almost as if you seem to have different motive, so I have decided to doubt your scepticism.