This is almost an appealing idea in a parallel universe where religion doesn’t exist, but unfortunately that’s not the one we live in. This conflict is one that extends to nearly every avenue, but at it’s core, it’s a religious one. Unless we’re ready as a global community to finally denounce religion and call the practice of it a silly and fruitless endeavor, which to be clear, we aren’t, then we’re never going to get anywhere pretending we can ignore the religious aspect of it. And that includes your utopian suggestion, which aside from all of its other very real problems would also likely enrage an enormous religious segment of the world who would see some of their holiest lands reduced to mere merchants dens. Even if you perhaps try to protect the religious sites, now you’re effectively enforcing a concept of religious sanctity on the global community, which is no less likely to offend.

Your idea is well-intended and nice to think about, but unfortunately unrealistic for many reasons, starting on the ground floor with problem of religion.