Could you clarify what makes you think it was? Judaism was founded there, as was Christianity. But the latter had its center elsewhere from an early date. As for the others, I'm not sure what gives you that idea.

I'm really not sure about focal point for religion and culture. However, the entire region of Canaan is located between Egypt and Mesopotamia (those were major focal points for culture and growth of civilization), which made it a pretty disputed territory.

Judea had no major significance in religion or culture, at least until Christianity was adopted by the Roman Empire.

The Middle East has been central to human beings since the first humans walked out of Africa. Since then, due to its position between the Fertile Crescent, the Persian Empire, the Mediterranean, and Ancient Egypt, it has been a center of a lot of trade of not only goods but ideas. In that sense, there was a lot of mixing of different cultures and ideas from many places in the Middle East. As such, such ideas evolved into unique religions taking elements from the Mesopotamian religions, Zoroastrianism, the Egyptian pantheons and religions and fusing and forging their own religious concepts from amalgamating and deriving from these other religions.