This is a recently published article about the problem of multitude in American poetry today.
I found it interesting.
The original link to the article on the subject that I particularly liked seems to have gone, but it was the original one that got me thinking, back in 2011.
The Problem of Multitude – it was to something called Samizdat.blog which has disappeared. There is a Samizdat on Facebook. Perhaps the original article is in its archives.
I recall that it mentioned that in 2010, there had been three anthologies of the Best American Poetry published, none of which included the same poets! That was a decade ago. All that is said in either link applied and does apply to UK poetry.
It’s a subject I’ve been thinking about for some time. I want to write an article about it myself. So in the future, I may post my response as a comment here.