Australia - easily.
First of all, cricket is not the only sport in the country as opposed to Pakistan where only one sport is being professionally managed and played. In Australia, kids have a lot of options and with the spot-fixing saga coupled with the dwindling performances of the men's team, cricket in general has taken a nose dive.
However, I would like to take this opportunity and say sports in general is at a critical stage in Australia, not just cricket alone. You just have to go back 20 years ago, when I would say Australia were the envy of the world when it came to sports.
1999 was a year that few Australians would ever forget. Australia had won the 1999 Rugby World Cup, came back from the depths of despair to win the 1999 Cricket World Cup, became Davis Cup champions in tennis for the 28th time and started their incredible 16 Test match winning streak. Lest we forget, Australia were also netball champions, Tri-nations rugby league winners, hockey Champions Trophy winners and also had men and women surfing world champions. Never in the history, I would believe any country on Earth would have had that many accomplishments in 1 single year. They were truly the envy of the world. And all this with less than 20 million population.
A year later, Australia brought 58 medals in the Sydney Olympics.
Fast forward to 2019, Australia has produced only two Grand Slam champions in tennis - Lleyton Hewitt and Samantha Stosur in the last 20 years. A country which has won the Davis Cup 28 times (2nd only to US) does not even find itself in the World Group anymore. At Rio 2016, they brought 29 medals - exactly half of what they got in Sydney. In the last 12 months, their cricket team has only won 11 games out of 39 across all formats. Squash which used to synonymous with Australia along with Pakistan, has vanished altogether.
Even the coaches are not choosing to coach in Australia anymore. Guys like Gillespie, Stuart Law are coaching county teams in England and not in Australia. Trevor Bayliss is coaching England and plotting Australia's downfall. Darren Cahill, the famed tennis coach does not coach in Australia. Eddie Jones coaches the England Rugby team.
I just read that in November, PM Scott Morrison refused to address calls to reverse a funding crisis even after more than 200 Olympians demanded a meeting.
So overall, it's not just cricket alone. Australia in itself is suffering from a severe slump in sports. Money is not being injected into sports at all. Ipads, PlayStations are also not helping as probably kids value the online world more than going out and playing sports which is why we are the seeing the shoddiest talent from Australia in decades.
It's a full blown crisis I believe, and Australia is facing it a lot more than Pakistan. And Pakistan will survive simply because it is the only sport in which Pakistani public can find a solace because the team is still somewhat capable of springing a surprise here and there. As long as public interest remains, Pakistan cricket survives. Same cannot be said of Australia. If they do not address this, the decline could be terminal.