They’re all underachievers to be fair. England the biggest ones but Scotland, Ireland and Wales are too to varying extents. England’s World Cup record is poor and about on a par with Croatia who have only been in existence since 1994 and have a tiny population.
Scotland’s inability to get out of the group stage of a tournament is pitiful. Ireland had a brief flare up in the 90s but have been garbage since then. Wales have just come off a brief flare up and probably on their way back to the wilderness now. They all have smaller populations so can be excused more than England, but still should’ve achieved more throughout their histories