Actually I agree that job creation is possible.
However there is no doubt that low-paid work is massively affected by immigration, since immigrants coming from a country like Poland will quadruple their back-home wages on UK NMW.
I don't think it's true that immigrants are necessarily underskilled, but what you will find is that with no UK work history you are going to struggle to get well-paid work, at least for a few years. Also foreign professional qualifications are not necessarily useful in the UK labour market.
For me the more fundamental problem is that we have a housing market that functions only with no net zero population growth, yet have absorbed several million foreign immigrants into the UK.
There are certainly employment areas directly impacted by immigration in terms of wages, studies have shown that immigration benefits the wealthy, but depresses wages at the low end.
"Over the period considered, estimates suggest that immigration held wages back by 0.7p per hour at the 10th percentile, contributed about 1.5p per hour to wage growth at the median and slightly more than 2p per hour at the 90th percentile."
Basically immigration makes the rich richer, and the poor poorer.
When you consider that the rich will tend to own their homes, and that over the course of the largest net migration in UK history, after 1997, that real house prices doubled, you can see that those who had, are much better off, since they owned their homes, which are now worth twice as much relative to their real wages (which have also increased), whereas those at the bottom, who don't own homes are worse off, with lower real wages, and housing affordability which, in real terms, is half what it was in 1997.