As several posters have previously mentioned, the problem lies much deeper. It's not just our first class system or cricket board, but the way our national sports are conducted.
The vast size of our country has allowed us to produce players with natural ability. We pick players purely based on their skills that they naturally possessed, for example Amir, Irfan, and Yasir. These players didn't get groomed from a young age, rather, they made it big on their own. For a national sports system to really thrive, a proper system must be established in which players go.
In U.S. for example, there are small leagues in every town where kids as small as three take part in. In other words, parents motivate their kids to take part in sports which contradicts to the mentality of a lot of parents in Pakistan.
As the kids get to high schools, they end up either choosing one sport to concentrate upon the most. Now whatever the sport may be, the players follow through a system in which skilled players are identified. Now they may go on to play in college and play professional football or simply not play anymore. However, skilled players are identified. As a result, players from the whole country have a chance to succeed if the skill is there.
Comparing that to Pakistan, the pool is already condensed as there are a lot of places in the country where there is absolutely no establishment of any system. However, wherever there is some establishment, the system has to reach out to them.
After identifying kids under 20, you have to work on them, groom them. I remember watching a documentary or something along the same lines some time ago. The BCB had sent over around 20 U-19 kids to train in Australia under an Australian coach. Now Bangladesh is reaping rewards for the work they had done. My point is, that players have to hand picked and then groomed in a proper environment.
It only makes sense if Pakistan is mediocre in sports looking at the system we have. We cannot produce players like Starc, Rabada or de Kock because there is no one to develop the skills of the youth in Pakistan.