I mean I get what you mean and I do agree that it plays a factor but your example here only makes a lot of sense for multiplayer games. CoD is a really good example of this in my opinion. The skins there are ridiculous and the amount of effort they spend to show it off is absurd for a full priced triple A game. On the other hand, most of Ubisoft's games are singleplayer so this FOMO effect doesn't really apply for those games.

I also don't think we can deny the agency of the player too if they do choose to make these purchases. If someone does do their research and justifies the micro transactions after looking at it rationally, is it fair to say that they've been completely manipulated? I've personally given money to EA for Titanfall 2's prime titan skins because I felt that it was a good value and wanted to support it. So I think there are somewhat more ethical micro transactions.