The biggest difference between English youth coaching and Barcelona, is that Barca uses half of the pitch when training younger players. Most English clubs use full regulation size pitches, and most English youth coaches only care about winning.
By getting big, tall, and fast lads, they overpower the opposition and easily win. Small and technical youth talents mostly can't even get a look in. Problem is, when they are older, physicality doesn't give that much of an advantage anymore.
More than just facilities, it's philosophy that must be adapted from Spain.