I assume you are referring to the refugee crisis. Nobody claims that refugees help with the economy. Nobody is saying immigration solves everything.
And as far as the places that have refugees where people are not happy about it, many people are insisting that refugees "help the economy" as a reason it should continue of course it's a narrow assessment and totally invalidates citizens concerns and that's the problem. Not to mention those pushing for refugees never seem to live in the neighborhoods where the burden or problems will need shouldered. It's always some moral stance rather than an empirical one and frankly a citizens preference to not have to deal with the trouble should be the first consideration but lately it hasn't been.