It also seems clear to me that in the UK and Ireland folks are far more interested in ballads--that is, solo storytelling, than many are in the US.   After all, the ballads in question by and large came from the UK and Ireland. They are yours, not ours, though we have our own versions.   There's the role played by Child.   But the ballads were still not home-grown American--they came from European sources.

Also, we are more likely to want to stretch the definition of folk--and 1954 is just a year. We watch you wrangle about 1954 with tolerant amusement.

For us "folk" can include virtually everything not classical or rock (and even rock is encroaching, since we are starting to do more doo-wop.)

Some include country, bluegrass, mining songs, labor songs, drinking songs, black and white gospel, labor songs-- protest songs of all types, black and white gospel, and probably more.    There are examples of many of these in RUS.

Yet another possibility is that folkies in the US have less time than those in the UK--maybe folks in the US don't retire as early.   That however is pure speculation--I have no idea if there's anything to that.

It's also possible that as the population ages and it's harder for folks in general to learn songs, UK version of a "folk hymn-sing" book may start to catch on. But it's also possible that the UK "hymn-sing book" will turn out to be an i-Phone or something similar.

But US folkies singing from RUS since they are used to hymn singing.   Not likely , to put it mildly.