I mean... not sure you could be more wrong if you tried, or to be honest make a more irrelevant comment.
The problem with trying to have a constructive discussion about immigration is that every knee jerk white supremacist British front loon tacks on to it like it is a call to arms.
Britain was built on colonisation, we were colonised by the Germans, Danes, Romans and French to mention a few (we used to mostly speak French up until around the time of QE1), and even before then we were not one people there were many vastly disparate tribes, Britain was not even a country until the act of union, we then went on to subjugate and colonise over half the world, and to put is politely did so by underhanded and violent means, half of which was done by private individuals acting purely out of financial self interest.
Many of the troubles we see in the world today are as of a result of Great British interference, Afghanistan, Kashmir, Palestine to mention a few
Despite our treatment of other nations, many men from India, Myanmar (Burma), West Indies to mention a few fought and died for us in wars, only to be treated as 2nd class citizens, after WWII we invited people from the commonwealth to move here to work and rebuild our economy.
And yet we get nonsense like your post about immigration.... half if not more of the people you think of as being quintessentially British are descended from immigrants only a couple of generations back.
You are also technically incorrect British or any other nationality is bestowed by birth or naturalisation.
Jim Ratcliffe needs to STFU he has zero idea about real life, has received tens of millions in subsidies from the British government and lives in a tax haven so he can avoid paying tax here, if there is a less qualified person to open his gob on the subject I am not sure who it would be.... maybe you!
FYI I have worked within the benefits system for over 30 years and I can categorically state that the vast and I mean vast majority of claimants are white British, and almost exclusively the fraudulent, violent, offensive, work shy claimants are white British.
People come here to work and do jobs that most lazy white Brits cannot be arsed to do... BTW I am a lazy white Brit but I do work!
And BTW stop painting the St. Georges cross on roundabouts will you, the appropriation by racists is really galling, and did you know that St George was actually Roman (present day Turkey) and never set foot in Britain, how is that for irony and appropriation?