The solution is to enable everyone to improve their quality of life where there are, as it's going to be impossible to come up with a system that is "fair" to everyone who wants to emigrate/immigrant. You can't craft immigration policy without a comprehensive understanding of how it relates to your country's economic and cultural foundation (are you allowing large amounts of unskilled labor in that is going to depress wages? allowing large amounts of immigrants in who might not want to integrate into your society and adopt your values? you're gonna have a bad time).

First world countries want the best of the best, not unskilled immigrants who they'll have to support. Developing countries aren't going to want to allow non-tourist immigration unless you have investment to offer. So we end up with this byzantine system of quotas and quid pro quo which treats people like pawns. Unpleasant and unsustainable for all involved.