Have mass migrations ever happened for positive reasons instead of because hardship or lack of opportunity in their home countries?

Just as a preface, I am not making this post because I oppose immigration or want to turn away imigrants, much less those who can't live safely in their home countries, I just notice immigration and misery seem to be intimately related, and it honestly makes me wonder if a world without misery is also a world without immigration, at least in the form of mass migrations of a specific people group or type of person. I also recognize that more immigration and cultural diversity does have a wide variety of benefits, regardless of it's causes or motives, and that leaving your home for some faraway country looking for some high-end job not present where you live is definitely not the fault or problem of the person migrating.

I've been thinking about immigration recently and it kind of astounds me just how much of immigration happens because of misery, Colonialism or oppression. Here's a pretty broad and varied list of mass immigration phenomena and (as I understand them) their causes:

• The USA has a southern border crisis (to some extent because Republicans like to exaggerate it to justify their xenophobia and so on) because Mexico and Latin America as a whole are much poorer than the USA (something the USA itself shares a good deal of blame for) and thus want to come to the USA, with illegal immigrants often doing so by any means necessary.

• Europe (and Turkey kinda) has an Arab migrant crisis because of the (mostly) failed Arab Spring and Syrian Civil War destabilizing the region or plunging it into war, forcing million to flee to Europe, which is in large part responsible for this crisis seing as (West) Europeans colonized the whole region and set much of the stage for conflicts.

• A large share of white people from a variety of different ethnic groups in the USA were fleeing oppression or misery in Europe (and the ones that were not came here to colonize and oppress the natives):

  • Quakers fleeing to the USA due to British persecution

  • Irish-Americans coming to the USA in largest amounts following the Potato Famine

  • The height of German-American migration to the USA followed the 1848 revolution's failure to make a more liberal and united Germany

  • Meanwhile, Black Americans, after being forcibly migrated out of the African continent to be enslaved, fled the US South in the millions starting around the 1920s as this was the nadir of race relations and the heights of the Jim Crow age. White flight to the suburbs (another large migration) was one of the main northern responses to this influx of black people.

• In early 20th century Brazil, the government encouraged immigration from European countries and Japan to them in large part due to a need for cheap labor still unmet a few decades after the end of slavery and as a way to make the country more white. Many of the European migrants were poor workers looking to make a better life for themselves.

• Zionism arguably owes it's existence and success to centuries of anti-Semitism in Europe and it's culmination in the Holocaust, alongside a sympathetic British Empire and UN being able to simply lease most of the Levant that they had colonized to a new Jewish state. This is layered on top of the fact that the reason Jewish people even left the Levant in the first place was oppression by several different foreign empires for centuries since antiquity. The modern state of Israel also owes the largest share of it's Jews from neighboring middle-eastern countries which also expelled them due to their own anti-Semitism.

• In the middle of the 20th century in Brazil, millions of Brazilian northeasterners migrated to the Southeast in search of economic opportunity they lacked (and to some extent still do) at home, as well as fleeing drought in more rural zones. Notably, in the 2010s we have seen many of these people return to the Northeast following Lula massively helping the Northeast develop over his first presidency in the 2000s. For a personal anecdote, both of my mother's parents did this, and brought my mother to where I live in São Paulo, and then they also went back to the northeast in the mid 2010s.

• Virtually the entirety of the Global South and also Eastern Europe suffers from Brain Drain, where their most educated people leave in search of better opportunity and higher incomes in developed countries and the multinationals they possess. Much of the USA's legal immigration and economic power in spite of it's numerous flaws is owed to this.

• Somewhat similarly, most Western European countries have one or more large communities of people who originate from a country they had colonized as an empire. (The USA also owes much of their Filipino American community to owning them despite it not being the same colonialism as practiced by the British on the USA or by Spain.)

Looking at this fairly long list of examples, I have to wonder if there are mass migrations that happened because of more positive reasons or if any of these already existing mass migrations can be explained by more positive reasons?