Well that does happen in real life actually. The shock factor can leave you stunned or struggling to move.
No, it's for a few other reasons, actually:we also know that the reason we don't get to see our WoL kick people's behinds cinematically is due to budget
- They can't know which class/job we are using and they can't future-proof it because we will have new jobs later on.
- They don't want to do the fighting for us normally. They want us to do that ourselves via the actual fights/dungeons/trials. The cutscenes are merely the setup for those fights.
Examples? The main Dawntrail one that gets referenced I do agree with them standing there initially out of sheer respect for Gulool Ja Ja's skill, which the WoL witnessed first-hand so they knew that they could handle it and technically they did by defeating Zoraal Ja.Stormblood was very guilty of it. Endwalker had few, but egregious moments. And then there is Dawntrail.
And really the second time, while it's obvious to all of us that there is some technology at play reviving Zoraal Ja and making them more powerful, the characters in the game are quite primitive and don't have a lot of technology like this so wouldn't necessarily understand this was a technology making them more powerful and considering Gulool Ja Ja won once, why wouldn't they again?