It still sounds dumb to me.
They forbade the Al-bheds to speak Spira's language? o_O
How do they do that? It seems way easier to me to murder a group of people than to forbid them to talk in a specific language. Plus several Al-bheds (Rikku or Rin) speak normally without problem.
Tidus still explodes by kicking a blitzball bomb. Why? Who? WTF?
That whole "summoners are actually gods" comes out of nowhere from my point of view. Ok, they have the ability to send the deads and summon magical incarnations of faiths (which is pretty badass already), but they need the consent for both of them (if the deads are reluctant to being sent, we need to beat them hard beforehand to weaken them). Besides, what's that gratuitous overbid of "summoners can not only control pyreflies but also create things out of nowhere" ?... And, as for Vegnagun in X-2 (well, there's at least an attempt of explanation for this one), it's very convenient to have a all-powerful being that didn't show up for 1000 years and apparently farmed tomatoes this whole time.
The resurrection of Tidus was very dumb in X-2 already, IMO. Maybe the faiths can indeed bring him back in Spira (there are faiths of Tidus and his whole family among them, so it's not inconcevable at all). But then, why didn't they do that at the end of FFX? They were not grateful enough to Yuna for that or what?
Also, I think the youtuber didn't understand what the "trivialization of death" argument means. How I get it, it's a matter of the importance and the impact of the deaths, not their commonness. When the party kills Seymour, it's a huge shift of the situation, when we learn that Mika or Auron are dead, it matters (Auron being dead is implied quite soon, so we can guess it and pay attention to the clues about it). Maechen being dead is the best character development of FFX-2 from my point of view ("development" in sense of "giving flesh to it"). So yes, death is omnipresent in Spira, but never trivial.