I have the citizenship of a country with which I do not share its politics, I do not share its culture, I do not share its economic structure, I do not even have things in common with the people who live in my country (being someone highly intellectual in a country where the incentive to science is almost nil).
And I am forced to pay taxes destined for projects that do not benefit me and that are built on ideas that I do not even share.
My humble and miserable vote in the next elections is not going to change anything in my country at all.
It is like being born in tribe "a", but having the culture of tribe "b", the political and economic inclination that tribe "b" has, even living better with the people of tribe "b", but being rejected by tribe "b" for the simple fact of being born in tribe "a"... It was a decision made by my parents and now I have to pay for something I didn't do? And there isn't even a way to fix it? Does the migration system of the countries currently have any kind of logic?
There is no argument (based on philosophy) to support the current migration system.
any constructive criticism will be welcome
It's impossible to run any kind of social safety net if an unlimited number of people can come in and bankrupt the social support.
Democracy also becomes impossible because if the native population gets uppity elites can bring in immigrants to dilute their votes. Mass immigration like this has, in the past, led to the end of large civilizations such as Rome.
Finally uncontrolled immigration economically crushes the native population by suppressing wages and causing asset and property price inflation. It's great for GDP over the short term though.
There's also the cultural and racial dilution thing but that's a controversial idea to say the least.
EDIT: I can't respond to you because my posts are throttled, but how does this work with your children? You have the same vote dilution problem in the new country but now it also opens up the opportunity to do the reverse if they're allowed to vote in the old country. Your "very long term" is likely multiple generations away. Should we be crushing the lives of multiple generations of our populations just take the best workers from these other countries and delay their development?