@Toomuchturroni agree with you on propensity to return being greater for the EU citizens and voted remain, but I think that it’s a somewhat overstated/oversimplified argument - there were still more than a million more EU citizens than the government expected who applied for settlement post 2016 and obviously millions more than the 20,000 a year predicted by EU enlargement to Eastern Europe did come to the U.K and stayed for quite lengthy periods, so it’s a general tendency and not a hardline rule. It’s quite stupid that government policy both whilst we were in the EU and afterwards is basically to assume that migration was temporary (impact of migration in official treasury statistics was measured over only a five year period, assuming people will go home before old age and not have kids and often still is!).
In addition, the position will likely be quite different depending on original country and background of the relevant person, as well as the performance of the birth country in the meantime (lots of Poles now returning to Poland in response to economic performance and incentives offered by the government) - all of those things are hard to anticipate in a blanket assumption, or to control for as a U.K. government and it’s not enough to say that it’s definitely not an issue, will always be covered by the economic benefits of EU membership and no one needs to monitor or think about it. If the EU enlarged to Albania, you might expect more permanent migration to the U.K. If a member state’s finances suffered a debt crisis, you might expect the U.K. to be more of a destination for certain countries’ citizens. There is also a downside to people leaving, as some of the EU citizens that are currently leaving will be very highly paid finance executives and entrepreneurs etc, who are very mobile and who we’d prefer to stay and pay tax, whereas those more reliant on state support are more likely to stay.
Further, if we had free movement, anyone from a third country who is given citizenship of an EU country (of which there are many since 2016) can come to Britain and stay as of right - such people might be more likely to come and settle permanently.
None of this is to say we shouldn’t have immigration, from the EU or otherwise, but just to try to add a bit of nuance, because I think that there is quite a lot of generalising in this debate, which helps no one, as it just polarises things further. I don’t think most people oppose immigration - they oppose lack of control/foresight and lack of fairness around required contribution - it’s not really clear, without reform to either or both of freedom of movement and the British welfare state (to require more contribution, as in other EU states) that this issue would be plain sailing politically. For this reason, I’d like to see a better standard of public discussion before any vote.