The problem with that worldview is that it's always the same look from the same perspective that is, the economic machine is an extractive system (top <- bottom) and the colonial system is entirely responsible for the current state of the countries a lot of people are trying to leave.

Your perspective ignores the fact that some of "us, the people" are actually benefiting from this economic machine/collective organization. In industrialized societies, it's been decades that even the people at the bottom of the social ladder have "more to lose than their chains". And no matter how morally responsible ex-colonizing nations are, it is a fact that newcomers have to be somewhat integrated economically and culturally and that no society knows how to do that at the scale of arrivals. It turns out reality is not as simple as our moral world is and it takes time and thankless work to figure out what's happening. Morality is somewhat well-equipped at handling relationships and at maybe detecting the economic/political systems failure modes but it is not well-equipped at solving societal issues.

The truth is that it is easy to attribute merit and blame but har to actually trying to make relevant change. Our vision of History is somewhat biased because we remember people who were responsible for positive change as people with the "right" position but it is often forgotten how much strategy, technical issues they've had to solve fort those to prevail :

https://www.amazon.fr/-/en/Waging-Good-War-Thomas-Ricks/dp/1...?