I've been wanting to create a similar holiday optimizer tool myself, but what you've done is marvelous! Do you take requests for new countries? I see that you're using https://date.nager.at/ as the source and country is listed, so perhaps it's easily doable?
I've added more countries now, feel free to see if it works for you :)
But clearly we also see some major downsides. We already have an epidemic of social media rotting people's minds, and everything about this capability is set to supercharge these trends. OpenAI addresses some of these concerns, but there's absolutely no reason to think that OpenAI will do anything other than what they perceive as whatever makes them the most money.
An analogy would be a company coming up with a way to synthesize and distribute infinite high-fructose corn syrup. There are positive aspects to cheaply making sweet tasting food, but we can also expect some very adverse effects on nutritional health. Sora looks like the equivalent for the mind.
There's an optimistic take on this fantastic new technology making the world a better place for all of us in the long run, after society and culture have adapted to it. It's going to be a bumpy ride before we get there.