You are certainly more diversely well-read than me. I have indeed been biased by my upbringing and only know something about half as many systems as you do.

But that's not how I arrived at where I am. I did not go through every belief system picking and choosing which ideas personally appealed to me.

When I grew old enough to question why I believed what I believed, it was all about evaluating the credibility of the historical record I was studying.

• Once I learned that is was by far the most well preserved, long running, and comprehensive history on the planet and
• I found the authors of that history to be credible, I realized that
• There really was a Person named Jesus who did and said incredible things.
• All of them told me that Jesus really was God in human form and therefore His words were authoritative.
• Therefore, I didn't go looking for other human-generated belief systems.

Now, if any of the other belief systems you mention can make it through such a credibility establishing process, I would be obligated to study them in detail too. Any that survived that filter would have to be compared and, if they contradicted each other, one would have to be selected over the others as the most likely historical testimony of what God has communicated to man.

So far, I've found nothing that compares to the pedigree of Christianity. Can you point to any others in the same league at all?