The problem for me is this.
Who was the last player we sent out on loan who became a successful regular first team player?
I can only think of Origi. Even then he had some success, was very popular with the fans but still went back out on loan.
We mainly use loans to fatten players up for the transfer market. The youngsters who are really good enough we chuck in like Trent and Gomez. Our rivals also do this and very few of their players make it either.
The strategy is simple, all clubs would like to pay nothing for top players and the only way is to develop youngsters with potential. However, at some point you need to give them game time to progress. They are then sent on loan and if they don't make it they are sold. Some get opportunities when there are injuries and if they are good they make it.