The irony.
You're basically the Messi version of Cal.
1. He's not the greatest ever.
2. He's already failed multiple times when taken out of the Barca setup against oppositions that were nothing great.
He doesn't have the aura that the other names you took who when had absolutely everything on the line just went ahead and got the result. (Wouldn't include R9 in that list myself, absolutely love him and he's similar to Messi in that he's incredibly talented but not exactly supreme in terms of mental toughness and leadership.)
1.
He called Messi
one of the greatest ever alongside Pelé, Maradona, etc. and stated that players of that calibre would stand out as the best in any era. Which I believe is a quite reasonable opinion.
2.
2006 WC : eliminated by Germany in
QF on pens (Messi didn't play)
2007 CA : lost to Brazil in the
Final
2010 WC : eliminated by Germany in
QF
2011 CA : eliminated by Uruguay in
QF on pens (Messi scored his)
2014 WC : lost to Germany in the
Final after extra time
2015 CA : lost to Chile in the
Final on pens (Messi scored his)
2016 CA : lost to Chile in the
Final on pens (Messi missed his)
Nothing amazing and Messi could and should've done more at times, but you make it sound like Argentina were clear favourites every time.
Compared to Pelé: everyone would be inferior because it's almost completely impossible to replicate that Brazilian era of success.
Compared to Maradona: they both have 1 lost WC final, but Messi's shy a World Cup trophy obviously (and more specifically the best performance in an international tournament of all-time).
On the other hand, Diego didn't do much in Copa América (while his NT won two of them with him absent in '91 and '93) and was also "thrown out" of 2 other World Cups (one by sending off, the other for doping).
He's nowhere near them of course in terms of NT legacy, but 4 international finals doesn't really fit with your description of it either, in my opinion.