The "play it out of the back' system is designed to get a result, in that, its a possession oriented style that is designed to draw the defense "in" and free up space in the middle and attacking third. The typical thinking has always been "if you control possession, you get a result", ie if you want to score, its better and if you want to "kill the game" its better.
For sure, it has it's drawbacks..The biggest drawback though is that if the opposing team high presses in your defensive third and clogs the passing lanes, it can cause you huge problems... you have to have the players who can pass well and stay on the ball when needed.
It does open up the midfield and attacking third, so if you have a really quality CM and good wingers, you can have a field day.
The problem with the US trying to implement this style (and again, kudos to the coach for actually trying to implement a style whereas his predecessors didn't really seem to have one) is that his defensive players are slow and not the best passers. Once they face that pressure, you see the mistakes and they are costly. You'll see it v Mexico, I guarantee this.
The US falls back to the "boot ball" style, which is boot the ball down the field and hopefully your attackers run onto it, there is a misplay by the defense or a bad bounce.
Again, missing 2 cogs in your midfield isn't helping the US. McKinnie and Reyna will help alleviate the pressure put on Pulisic. As it was in the first 3 games, it was basically a defensive strategy by these other countries of "Foul Pulisic. Be Physical. As soon as he gets the ball, have 2 people on him. Force the others to beat us. We'll take our chances on them not being good enough to beat us." It worked in the first 2 games.
Wejo, don't fall for the recency bias :)
I don't think the US is better without Pulisic. There is no way. See what I said above. He needs some quality around him...I'm sorry, but Kellyn Acosta and this Sands dude as your 2 central midfielders? No. Just no. They might grow to be great players, but are overmatched right now at the senior level. When Gio Reyna and McKinnie are back, its a much different team and midfield.
Pepi could be a stud for the US. I've seen him with FC Dallas and the skills are there. The thing with strikers is they run hot and cold. When they are feasting, they are amazing. When its a famine, well, you get Bobby Wood or Wondo with the USMNT.