But I feel like the feeling of doom and futurelessness that’s so pervasive in the US is probably also a problem in Japan. To be clear, I’m basing this purely on vibes, not any data.

Yeah, vibes are pretty hard to quantify, especially across vastly different cultures. In my personal experience, the doom and gloom is much less prevalent (and frustrating) than the grill pilled political apathy.

Still, no one should tell you how to feel about moving to another country, so best of luck escaping from that American hellscape.