Sweden went from almost entirely ethnic Swedish, with high levels of social cohesion and trust (easier to achieve in a monoethnic country), to one quarter of the population now being of a non-Swedish ethnicity, in a span of 50 years. It is now one of the most crime-ridden countries in Europe[0], with some having described it as the "grenade attack capital" of Europe.
I don't know why some keep on insisting that importing large numbers of people from vastly different cultural, political, and economic backgrounds, with neither a real plan on the government's part to integrate them nor a factual evidence of the immigrants being able to integrate well, is a good idea. Even worse are the blind accusations of racism when someone questions such policies.
I'm an immigrant myself (though not to Sweden), and I don't have anything against immigration; only the idea that people have an unrestricted right to be anywhere they please and behave in any way they please. "When in Rome, do as the Romans do." An idea so old it's literally from the Roman Empire.
Nobody wins in the scenario of Sweden: not the native Swedes, not the immigrants who want to integrate into Swedish society, who now face additional burdens of discrimination.
[0]: https://www.numbeo.com/crime/rankings_by_country.jsp?title=2...