Sweden has taken in way more immigrants than our systems can swallow, this means the system as a whole is leaking. This has lead to lots of segregated areas where there is no future, just people living on welfare getting nowhere in life, as much as 60% of kids fail to even finish High School in these areas, even thou they get 3x-4x of the funding compared to other schools in "good areas". And you get NOWHERE in Sweden without education.

The vast majority of the immigrants is also men which has skewed the male/female ratio in certain age groups.

The violence we see now is mainly from second-generation immigrants because they have no real connection with their home country and they have no real connection with Sweden either since they have grown up in areas where there are no Swedes.

These aimless young men + a system that have failed them + a fast growing gangster culture that promises money and respect + no real consequences for young criminals (4years max for murder, rape is a couple of months maybe if anything at all) leads to a very fast growing criminal networks / gangs.

The gangs now also have an endless supply of young men willing to do whatever it takes since we a constantly taking in more people even thou the system is showing no signs of being better at integration people.

I wanna be very clear thou, this is not due to race/skin-color or other racist bullshit, it is simply input vs output, ANY system in the known universe that gets overburden crashes or starts behaving in unfavourable ways and that is where we are now.