I think you are probably right here steadyeddy.
looking at the records set by men in the 6 Lakes classics, Welsh 1000m, Snowdon, 3 peaks, Edale Skyline, Ben Nevis, only one has been broken this decade (Duddon 2007 Ian Holmes).
It’s interesting to note that 6 of the 11 records were set between 1977 and 1986, a period of time that seems to generally coincide with the best performances by British male distance runners on the road and track.
A noteable trend is the dominance of the names Bland and Stuart, and the number of records that have stood for 20+ years. I wonder how many people have got within ½ an hour of Billy Bland’s 1982 Bob Graham round record? I suspect not many.
For the women it appears to be a different story with some superb performances being registered this decade and a number of them more recently. Janet McIver’s impressive season last year winning the womens category in 5 of the 6 Lakes classics, taking 3 records (Duddon, Ennerdale and Wasdale jointly with Jackie Lee), as well as Fairfield horseshoe. You only need to take a brief look through the handbook to spot that a large number of womens records have been set in the last decade by a variety of different runners, i.e. Angela Mudge, Jackie Lee etc.
This also seems to coincide with the road/ track with the all time best performances at 10 000m, 10K road, Half marathon and marathon being set in the period 2002-2009 by Paula Radcliffe and the likes of Mara Yamuchi and Jo Pavey having registered times in the all time top 5 over these distances within this time frame.
My feeling is that British mens distance and fell running peaked in the 80’s and womens distance and fell running is probably better now than ever before.
But all things are cyclical and there are some good young fell runners around at the moment so who knows?