I think the full phrase ‘net immigration’ is very important, OP. In my experience most who don’t use it don’t understand the difference. As you do, I apologise.
Thank you for the link to the Migration Laboratory report. My connection is currently wonky, so I have only been able to scan the first part briefly. My reading thus far agrees with @KrisAkabusi . Could you please explain why you interpret the report differently?
I look forward to reading the whole report soon.
The standard entry route to the UK is the Skilled worker visa which now requires a firm job offer with a minimum income of £38,700. The median UK income as of April was about £37, 400. So present policies require relatively high earnings for entry. The jobs with those earnings usually require decent English.
Many children also learn English at school, particularly in Africa, parts of Asia and the Middle East. Obviously learning in a new-ish language is challenging, but there are lots of resources and many, many pupils all over the world do this successfully. The younger, the better, of course. Parental attitudes are very important.
The new regulations will probably change the faces of immigration to some extent.
Most British do not start out with capital at their disposal. ( Whether you have access to The Bank of Mum and Dad is becoming a great divide amongst YP. ) I can’t see that immigrants mostly failing to bring financial capital is of great significance.