Chances of those succeeding is close to nothing, though.
It's like wasting cash and expecting Empoli, Sampdoria and such teams to ask for those players, so we could swap for 'better' talents.
I'm not saying that there aren't cheap talents out there, but it's not like they develop into something great. Chances are bottom low.
Firstly, how do you know the mentioned players will succeed or not, or the likes of Bouy, Chibsah, Untersee, Beltrame, Padovan etc? All low cost signings. It's pretty obvious that only a portion would ever play for Juventus, if that is what you mean by 'succeed'. It's obvious because in a team like Juventus you can only fit so many young players into the first team at a time, even with the best of intentions. Even teams like Arsenal and Barcelona suffer from this.
Secondly, there is no 'waste of cash' here. When a system is ran correctly, as ours has been for the last few years, it more than pays for itself, maybe 3-4 times over. You get value by having players come through to make the first team squad - saving the club tens of millions (Marchisio, Giovinco, De Ceglie, Marrone etc), and you make several million selling those fringe players who were brought in for pennies at a time (Ekdal, Ariaudo, Immobile, possibly Pasquato, Giandonato, Rossi etc). If you bring in 25 players for €0.1m and sell only three of them for just €1m each then the system more than pays for itself.
Juventus are making money from the youth system, the success of it is not just to provide players for the first team. That is the ultimate aim but clubs well know that few can make the first team. It's a smart business plan, that other clubs make a lot of money off.
If we spend €3m each on two players 16-18 years old per season instead of having our youth program then what happens if they don't turn out as good as their early promise? You're essentially saying we should abandon the youth team and do this instead, as if a price tag is a guarantee. The point you are missing is that the aim is to identify the right players early enough so we don't have to pay €3m for young players, they are there ready for us.
The added bonus of bring through your own youth players is that they have an affinity to the club and are a strong link between the team and fans.