Right, I'm not saying Barca would be the same if you just took Messi out, obviously he is an integral part of the team. I'm saying, Barca would probably look very similar if you replaced Messi with any certain other similar world class players.
But this is not to be confused with a statement that Messi isn't a contributing factor on Barca. In fact, I've said it many times before, Messi is clearly the best player on Barca and probably the entire world at this time. That is however a different statement to saying "GOAT."