Well, I guess if you left out Salvador, Guatemala and Honduras out is for the reason thst you well know that US contributed well on the feck up situation those countries are in. Right of the bat we already have 3 countries of the top 5 that contributes on the illegal immigration problem in US
As for Mexico at the top of my head, you can find operation condor and the dirty war with indirect involvement of the US when Mexico was starting to get too communist for US likening in certain stages. That means assasination of politicians, killing farmers and local leaders and of course the war on drugs with direct influence from the CIA and DEA in building the networks of the new mexican cartels (thanks "narcos") leaving Mexico with a big problem in the country with hundreds of thousands affected and leave their areas to not get caught in the middle of the shit show.
Another factor is the constant drain of the best professionals of Mexico going to the US, draining the country of the best not staying there lifting the country to a better state. I can't blame either of the parts as you want to improve and the companies wants the best, but results are damaging Mexico as it costs Mexico a lot of money and US ends benefiting of
It is true that a part of the immigration of Mexico is the desire to just simply improve, but if the country would be in a better shape, they will not find the necessity
And example is Spain, in the 60/70s spaniards immigrated to Europe en mass for economic reasons. on the 80s-00s, as the economic situation improved, even if there were other ocuntries better off, as the inequality between them it was not a lot, people preferred to stay in Spain. Due to the economic situation in 2008 and the aftermath, inequality grew and spaniards started to immigrated again. A new sudy shows that in from 2018-2022, 400.000 spaniards immigrated costing 150 billion euros to spain. And spain is doing the same to latinamerican countries.
And again, I understand, everybody wants to do better and also, is not everything or always the US or EU fault but local governments has a big portion of the fault. But paying the price locally because local reasons is your own fault and you have to suck it up. But paying the price, even partially, for external reasons is not fair and is even more unfair is when this external sources cries when the consequences gets them
All in all, I understand why immigration exists, some are nasty consequencies of fecking around. Post colonialism, coup d'etat, wars. Others are economic immigration caused by inequality
What is selfish is that the west wants all the good parts of dealing with these countries (cheap labour, the best qualified of these countries, natural resources, etc...) but none of the negative consequences. And when I express this, I am not insensitive on the people that suffer the negative consequences of mass immigration, but I think is important to know why is happening and try to elevate the discussion to the causes and what it can be done to solve them to find a solution for them and not try to avoid the negative symptons and just speak of these symptoms that are undesired mass immigration
In the end, this is not caused by US, EU or locals. Is caused by capitalism, and the ones on top of capitalism happens to be the west