@CoatRack
Growth has been dismal since about 2007, but since 2010 per-capita real GDP has in fact increased, even the median (from £27k to £32k, after inflation). I don't know if people feel richer or not, though objectively the median person is. But I don't see a link between feeling better off and immigration. Purely anecdotally, I'd say the most optimistic national mood was under Blair, when he increased immigration substantially, as well as tightening up some controls eg on crime and asylum a bit.
I think the main reason growth has been weak since 2007 ish was the global financial crisis followed by austerity.
NHS and social care. What are your sources please? From the HoC Library I can find NHS 19% non-British workforce vs about 9% for the country overall.
As for net contribution to public finances: research typically finds a positive impact on public finances. Eg the Oxford Migration Observatory and the OBR (neither of which are especially lefty).
migrationobservatory.ox.ac.uk/resources/briefings/the-fiscal-impact-of-immigration-in-the-uk/
What this obscures is that: I) there is a huge difference in the public finances effect of immigration from different countries (I've not seen this data for the UK but have for other European countries). While I value immigration for reasons beyond public finances, this is a legitimate subject of public debate and there's nothing nefarious about pushing for a bias to more-contributing migration vs less-contributing.
II) the massive one: life stage. Old people are very expensive. Immigration is not a Ponzi scheme because many migrants come here to work and pay taxes, then leave. This is another reason why the NHS/social care impact wouldn't cancel out to nil even if the proportions were the same as the population (which they are not).
Most immigrant visas state no recourse to public funds.
But economics is more than public finances: immigrants both buy and sell things in the UK. Provided noone is forced to trade, having a larger market makes people on average better off. Making sure that that benefit is fairly shared is important. But I'd rather we were dividing up a bigger pie than a smaller one.
Thought experiment: would (say) North East England be richer or poorer if noone were allowed to enter or leave it? I think poorer.
Beyond host-country economics, I also like immigration on other grounds: i) unleashing economic human potential by connecting talent with demand: transforming someone from a provincial accountant in their home country into a Google software engineer in Cambridge (at 20x the economic value) is a net gain for the UK and for humanity. ii) provided legitimate problems are adequately addressed, giving more people more choice on where they live is a win for liberty, which is a good thing all else equal. The US, for example, is better because its citizens can choose to live in any state. I'm not a border abolitionist, but freedom goes in the plus not minus column.