You just can't move a game server from dedicated hardware onto AWS

Think about when you play the game, every single action you and every other player and every monster needs to be calculated and the result sent back within 20 ms, 24/7, without even a single delay. Unlike Google or Amazon which can occassionally take a second or two longer to load a page and no one will notice, in a game if you lag even a little bit and even if its only once in an entire fight, it's really obvious. Even livestream sites like twitch don't need this kind of performance, because their video is buffered, it knows what to send seconds before it needs to. FFXIV needs to react to your actions almost instantly, even though the calculations are simple, the consistent responsiveness makes it pretty specialized.

And services like AWS and Azure just aren't designed for it because online games are smaller than the thousands of small and large tech companies that do use AWS, companies who care more about ease of development and scalability rather than microsecond performance. And AWS gets designed for those companies instead.