Recently I have become convinced that the only really effective solution to the global migration problem would be to cut off the flow of migrants from the regions (from Afghanistan to Venezuela) which are the sources of the migration. That would mean tackling the vast political and economic problems within those regions, plus preventing them being exacerbated by climate change (which can add more from island communities).
Being a realist, I accept that such a solution is impossible in any complete sense. The level of international support - across geopolitical divides - needed to work it would be utopian fantasy. That in the literal sense of 'utopia' as 'no place'. Exiting refugee and asylum conventions, which do need to be updated, sounds like an easy fix for individual countries, but would mean leaving the migration sources an open target for troublemakers and 21st century imperialists. The most that might be possible in the short term is piecemeal pragmatism; efforts to move to green technologies as fast as possible, revamp the immigration control system to cut into the lucrative people smuggling trade, backing charities or aid aiming to help more people find a future for themselves and their families at home, and grinding diplomatic work on the conflicts around the world and adjusting asylum and refugee provision. All unexciting stuff. In the meantime, level with the public that such grind is the best they can expect, given the geopolitical and religious realities.
Migration is one of those cases where I would be only too pleased to see more become possible, but I plead against promising more for now.