One of the great conundrums of rugby around the world was, for years, that the Irish didn't embrace 7s.
Ireland as a 15-a-side nation played a pretty attractive style of rugby. It wasn't as if they were afraid to run and pass and exploit all the space that manifests when you reduce the number of players by more than half and keep them on the same-size field of 100 meters by 70 meters. With Rugby 7s being a game centered on running free and passing, you'd think Ireland would be a world power.
And then you look at the Sevens World Series. The moveable feast of international rugby is a festival, a rugby party. Those who haven't seen it, especially non-rugby fans, marvel at how fans if different nations comingle, get along, and often start adopting their newfound friends' nation as a second team to cheer for. This is classic Ireland. Irish rugby fans are known worldwide for being great sports—win or lose, the Irish rugby fan will raise a glass to the game.
So it was always a surprise that not only wasn't Ireland a world leader in 7s, they didn't event participate in the World Series.
Then the Olympics came along.
Ireland, after navigating the delicate issue of a Republic of Ireland team (Ireland, Northern and Republic of, have always played as one nation in rugby), the Irish marched off to try to qualify for the Olympics. They didn't qualify for 2016, but there they were in 2020. Meanwhile, those in the head office realized they could keep the Olympic flame going by doing well at the World Cup in between Olympiads. And, of course, to stay current there you'd need your team playing at a high level all the time.