Is the issue the level of immigration or media/social media campaigns (both controlled by rightwing billionaires) that have seen reported concern rising even as the actual level of immigration has crashed?

I don't disagree that the media (both social/mainstream - I would add BBC too) has played a key role in driving the salience of the issue, but that doesn't change the situation that the public believe this is a problem that needs to be sorted (even though the data suggests it is already falling).