Could you elaborate further? I am a skilled immigrant in the UK. I pay my taxes and have not used any benefits. I even pay for my medication; the only free service I have used is a GP appointment or a hospital scan, which was likely covered by the IHS (Immigration Health Surcharge).
What have I done to make the country worse off?
It's nothing against you personally. I'm sure many immigrants are good people and some scarce skilled workers must be imported. But there seems to be a desire from the top to import too many foreign workers across the West. This contributes to the low wages and lack of opportunities described in the article.
The UK also has outsourced a lot of manufacturing, which further worsens the job market. I don't know how many hardware engineers are imported unnecessarily or else part of "offshoring," but by all indications I've seen personally the number may be significant. This is from an outside US perspective, so take it with a grain of salt.