If you had an influx of say 100,000 people that would be enough to disrupt labour markets due to supply and demand and that would reduce wages and total avaliable jobs to the native population. So from a native point of view you are looking at either being unemployed or having a job at a lower wage.
Now if another 100,000 people came into the country and didn’t work and was on benefits then as a native your taxes are going to them.
Those two groups of people don’t impact each other. So both statements can be true. Low paid workers don’t tend to create jobs. So from a low paid point of view you got nothing to gain from immigration.