The expansion was set against the backdrop of the literal end of the world. Of course there was supposed to be tension. And it could have been alleviated every once in a while by scenes far less ridiculous than the hamburger sequence. As others have mentioned, it isn't that we were immune to the tension, we expected and wanted to see it instead of the fluff scenes. If we wanted to play a silly high school style game then we would be playing Persona instead of Final Fantasy XIV.
I once again insist that G'raha Tia's writing represents both a failure of the writers to commit to meaningful sacrifice (a trend we later saw repeat itself in Endwalker) and the prioritization of comfort over substance. Heroes staying alive is more heroic than sacrificing themselves for the causes they believe in? I'm sorry but are you kidding me? I think we have completely different definitions about what it means to be a hero. The High Summoners of FFX were praised as heroes because they gave their lives in order to bring peace to their world even if it was only temporary because they held on to hope, even if they were not told the full story of Sin. Noctis in FFXV saved the entire world by sacrificing his life after having enjoyed a relatively privileged life up until the invasion of Insomnia. Need I go on?
What we saw there was the product of "covid writing" where during that era I noticed that many writers (myself included) were unwilling to put their characters through a lot because of how bleak everyone's irl situations were. I recognized what had happened there on the spot. He didn't get a happy ending because he deserved one, he got one because people were understandably not in the mood to write that kind of ending for him at the time, even if that was what would have made the most sense for the story. 2 years later we are still paying the price for that decision, with one of the best characters in the game reduced to a bad joke.