While I know I've lived many lives, I've also known a few people, two of them very close to me, that I'm sure had very few behind them. They were very handy with menial tasks, had done quite poorly in school, and were only a couple of steps away from being illiterate. I believe they were very young souls. One was my sister, another was a man that I'd loved. He only knew how to sign a check, but left the writing of it to others. They both had other characteristics that put them at a base level of evolution. One of my other sisters, next to this one, had an IQ around 160.
Over my lifetime I've come to believe that we're all going toward a goal of becoming - I'm not sure what the term would be - perfect? By living through all of the conditions of living, which in one lifetime is a very small number, we will eventually reach a time when all the negative things are gone from us, and instead of hating, destroying, and all the rest of life's negativities, we become highly educated and find the way to banish all diseases, and death itself, since we'll no longer have need of it. We'll nurture our planet and all that's on and in it, and maybe have another, perfect, planet to live on since there will always be new souls climbing that ladder on this one, and possibly other planets in the universe.
I'm sure I don't fit in with the majority of people here because I don't read the books then pick and choose what appeals to me. I've never read anything but history and historical fiction, Science Fiction and Fantasy. I've mentioned before that I've never given any thought over the years about reincarnation. It was only a few years ago that what I've written here was one day in my mind. Even then I'd only given it a cursory run through, but it all makes perfect sense to me.
I'm of the opinion that we are all on different levels of advancement, and no two people agree on most things, so we each will eventually come to the conclusion of what feels right to us, and I respect everyone's beliefs.
To Sea&Sky
On the topic of new souls, if we look at the numbers of people on the planet now, as compared to say 1800, there has to be some answer to the difference in numbers. I think your second paragraph points this out.