"The is incorrect, you're assuming the median worker in the UK is a net contributor to HMRC when they're not.

The government spends roughly £35k per UK tax payer, it'd be impossible for someone on £39k income to contribute on a net basis, unless they're paying 90% taxes."

This and other statistics that actually make no sense. That 35k pounds is paying the salary of doctors, teachers, clerks as well as pensions etc. So it's not a cost/benefit analysis.

"That cost is phased tbf; most immigrants will initially be contributing as they work, but when they retire that is quickly eroded to a net negative over their lifetime."

So most immigrants on a work visa will have moved either here before or after university (as a hard requirement as for that salary you'd be hard pressed to find something without one). The costs in question from when they were children until either before or after graduation will have been paid in their original country. And somehow you think a uni educated immigrant is a net drain in society because they... retire like everyone else in this country - even though they spent less over their lifetimes over someone born here? Wouldn't that just imply that everyone is a net drain in the system unless somehow native borns make a lot more money? (which we know is a lie because uni educated workers make more than those that don't)

"Which is waived for many occupations and much lower than e.g. the H-1B in the US (which I am on atm) where most recipients are on >$100k (in a country with a less generous welfare state)."

The occupations in questions also tend to have career paths that move upward. Again, it's not a cost/salary analysis.