That's understating it somewhat. He scored or assisted practically every goal in qualifying. I think they picked up one point without him, and before the tournament hadn't scored a goal without him in about two years.
As underwhelming as they have been, they are absolutely diabolical without him, and wouldn't have even qualified without him.
There are a couple of good players coming through in Dybala and Pavan (Icardi, to an extent), but that's not really going to solve their problem. They have amazing attacking options already - Messi, Aguero, Higuain, Di Maria etc. Dybala and Pavan are probably downgrades on those, but the real problem is the lack of ability elsewhere.
Not one single keeper, defender, or midfielder from the Argentina squad would get into the France squad. They might not even get into the England squad. Their defence is so bad that Funes Mori got into the provisional squad. Their leftback can't get a game for Ajax. Their first choice keeper (before he got injured, anyway) played 10 games this season. Their actual starting keeper at the World Cup played a dozen times. Their fall back keeper, who started this match, was making just his second appearance. Their midfielders are almost all in their 30s - Mascherano, Banega, Biglia, Perez. Mascherano is semi-retired in China. Perez is semi-retired in Argentina. Of their young midfielders, Lo Celso can't get a games, and Meza is still in Argentina at 25.
Of course, Sampaoli didn't help. That backline against Croatia (two not exactly brilliant fullbacks either side of Otamendi in a 3), and Mascherano and Perez up against two of the best central midfielders in the world, was one of the worst tactical decisions I've ever seen, and I watched us line up with Evra, Carrick, and Fletcher at the back.
So, as much as they do have some attacking talent ready to come through, it's questionable whether it's actually an improvement on what they have, and it's pretty clear that the real problem is everywhere else.
I only wish I could throw shade as innocently as you did. TF stands for 'the future', I stands for 'is', and I'll let you guess which former Utd player the A stands for.