The implications of time dilation when moving near c are also explored in the Three Body Problem trilogy, and pushed to the extreme as well. It’s quite a mindfuck if you still have ties to the place you’re leaving, but interesting if you don’t.
There’s all the interesting idea of just accelerating forever, till the end of the universe (which comes faster than you think if you’re going that fast).
We're really spoiled by modern rapid global travel. In the 1930s half of my maternal grandmother's family emigrated to New Zealand. I've only ever met two of those relatives once in the 1990s, but before jet travel such contact was impractical for most people. That's why whole family groups, or even communities would move together.
There’s all the interesting idea of just accelerating forever, till the end of the universe (which comes faster than you think if you’re going that fast).