He's a wide player who was playing in a really crappy 3-5-2 and expected to make nearly everything happen as a striker leading the line, what exactly did people expect? England chucked long balls over the top to him constantly which he doggedly chased and mostly made the best of. He was by far our most threatening player on the ball and pretty much the only England attacking player (Aside from on occasion Lingard) who actually frightened any defenders all tournament, from open play.
Yeah, he messed up a few chances he should put away. He's a terrible finisher, but this isn't something new. He's always had zero composure in front of goal and poor technique when striking the ball. He's never going to lead the line for any team and be a success, because that isn't his game. His strength for City this season was popping up in some excellent areas, he scored a ton of tap ins from balls across the box to pad out his stats. Nothing wrong with that, but you can't look at those goals and say he's a player who leads the line. He's a support player who benefited from some fantastic players around him, he's a really good player with excellent dribbling and pace to terrify defenders, but a bit of speed does not qualify you to lead the line at a World Cup. Go look at the video of all his goals in the 2017/2018 season, does anybody see a striker? This isn't even taking in to account the massive added pressure which comes with playing for England at a World Cup, especially when you're a player who has been shredded in the past. He was never going to be calm and composed.
He basically played exactly how I expected him to, a wide forward shoved up front so he could be shoehorned in to a system which clearly never fitted him, or pretty much any of our attacking players. It's something Southgate has to work on, but it isn't Sterling's fault, you can't expect him to suddenly become a different player just because he put up some good stats in a completely different City system in a totally different role, it's ridiculous. Anyone who expected anything different from him in this role was going in with unrealistic expectations, sure you can say a few opportunities he should score regardless of positioning, but he misses plenty of chances for City too. It's just they create loads so it often doesn't get highlighted as much.
@CassiusClaymore you mention Alli as being worse and you're right, he was constantly giving the ball away and a complete non-threat. That's what you get from Dele Alli in CM though, especially in a system where the other players won't be able to carry him. I think most Spurs fans could have told you from the start that if you play Alli in that role/position he's going to offer you nothing but losing possession and looking lost. He needs to be as close to the striker as possible because he's basically a shadow striker, in that role he still won't offer that much for the 90 minutes but he will give you goals and assists. His movement in the box is world class, but again Southgate has him in a role that he's woeful in so nobody should expect anything. It's not like these guys are bonafide world stars, they aren't going to thrive wherever they are on the pitch, they are players with clearly defined strengths & weaknesses which their club managers have identified and thus best utilized them in roles that suit the strengths.