TBH I grew up in what is now considered to be Greater London, in fairly leafy areas, and I don’t ever remember seeing a murmuration. I’ve still never seen one in the wild, only on film - would really love to, though.
We live in a similar GL area now and I haven’t seen a starling for ages, but we used to - they used to mimic the ring of a particular type of phone - the Trimphone I think it was called.
A dd living in Oxfordshire still gets a lot in her garden though.
I do often wonder whether the vast increase in magpies since they were protected, has anything to do with the decline in certain smaller birds. We see so many magpies here on a daily basis, whereas they used to be a rarity. They must account for so many losses of nestlings and young birds.