Interesting. I was looking at the numbers of cases, which seem as high now as they were back in January, although the curve is less steep.
Not true - reported cases in Jan were considerably higher than now, and there were fewer tests being conducted then as well.
But herd immunity isn't just restriction to infection, but disease. So one of the major features of the vaccine is that it reduces severity of disease and of course plenty of the people testing positive are completely asymptomatic - and we only know they are positive due to our testing regimes. In normal circumstances if an infection was being passed around without generating symptoms we wouldn't be able to tell this from a situation where there was no infectious transmission.
There is no doubt that we are much closer to herd immunity now than in January and that is due in a large part to vaccination, but also ongoing infections within the population too.
As was pretty easily calculated from back of fag packet calculations way back in March 2020, getting to herd immunity without vaccination would have resulted in many times more deaths than we've seen.