Haredi don’t tend to migrate in large numbers, and the last big wave was in the 50s. Most of them were born there. Their parents + grandparents + great grandparents mostly moved there either during Mandatory Palestine or right after Israel was established as a state. Most of the Jews moving to Israel recently are American and European reform/conservative Jews.
Most Haredi oppose Zionism as like a core principle. They think that only the Messiah can establish Israel, not humans.
But some that are born there live there for the same reason your average Death To America left type broke white person still lives in America.