We have a similar issue in the UK. The government has refused to provide enough resources to process the backlog of asylum applications, so people are left in limbo being housed in hotels with no legal rights to work or anything. It costs way more than just processing their applications and allowing them to work, but the government are too scared of looking 'soft on immigration'. And these hotels are often in poor and disenfranchised communities, so people understandably ask "why are they getting hotels paid for by the government when we have such a lack of social housing?". It just creates more tension and doesn't help anyone.
It's also important to separate the different kinds of immigration. Refugees are a very different category from other migrants, because we have international obligations to grant them asylum in legitimate cases. So lumping them all under the banner of 'immigration' isn't really helpful.
One told me that he worked since age 8. Not being allowed to work put him in a completely alien position. On top he was now living from other people's money, like children, old people, handicapped or sick. He was enraged by it.
He kept repeating I've worked 7 days for 30 years, I don't know how to sit on a sofa the whole day. He was getting weak, lost appetite, couldn't sleep. Every day was supposed to be a challenge rewarded with food for your family and a warm bed.
He was 3 months into the process and was clearly going insane.
The real problem is that there are several contradicting ideas at play. You can help people but you do have to employ and tax them asap. If we can't do the work the conveyor belt must slow down. You can house people but you do still have to house everyone. You can't help people by giving them other people's houses. You can assimilate people but speed and quality decline at scale.
You can tax to death and shut down social gathering, clubs, pubs, restaurants and libraries to prevent people from organizing against your sinister agenda but your assimilation capacity will greatly suffer. You must choose one.
How many natives get angry should also play a big role. Angry people are poor assimilators.
There is also a national security angle. If foreign parties want to organize a civil war for you you don't have to make it incredibly cheap and easy. To much nationalism is an ugly thing but the opposite can end the country.
It's also important to separate the different kinds of immigration. Refugees are a very different category from other migrants, because we have international obligations to grant them asylum in legitimate cases. So lumping them all under the banner of 'immigration' isn't really helpful.