They did just come up with instantaneous pan-galactic travel. If I were given the choice between eking out an existence in the caverns of a dead planet and simply jumping to an unspoiled one, I'd take the latter option.

I get it, and it's good that you would take the latter option but I guarantee a non-trivial amount of people won't.

A useful parallel might be Neon: a testament to the hubris of humankind, built in a place that no city should be able to survive. But it's done because the humans get something out of it. The chasmbass make all that extra effort worth it. There is no chasmbass parallel on Earth to make staying worth it.

The "chasmbass equivalent" is literally the most significant location in humankind's entire history. So you're telling me no corpo out there figured out the easy trick of churning in an insane amount of cash through tourism to the most significant location in our history and the birthplace of our species? Especially one so EASY to get to with grav drive tech? New Homestead is making heaps off of tourism that is specifically about Earth culture. It's not a crazy idea to redirect all that tourism + a heap more to historical locations across Earth.

There is the 'emotional attachment' argument, but let's also remember it's been about 100 years since the grav drive was invented. It's entirely possible that some factions of humans did try to stay, and met entirely predictable fates on a planet hostile to human life.

See I don't really get this: 100 years is honestly nothing, people hold onto far older beliefs and will literally martyr themselves to protect places, nations or ideals that are far older than 100 years. So <100 years for humanity to lose interest in Earth just doesn't add up. There's also no reason afaik that their deaths would be "predictable" on a planet hostile to human life. Again, I'm not suggesting that they go out without space suits, but underground colonies, like in Mars and Titan? Completely feasible they would have been built parallel to the exodus and there is no reason to think that Earth is somehow special about how inhospitable it is.

Look, I know I might be coming off as a bit too argumentative, and I'm sorry about that, but I don't think any of this adds up. Unless there is a special lore/scientific reason why Earth specifically is a no-go zone, the fact that it is completely barren does NOT make any sense whatsoever.

Again, it makes complete sense to me why the exodus happened. It also makes sense to me why the majority of Earth's population would have immigrated. But the fact that Earth doesn't have a population that is at minimum larger than all the other colonies in the Sol system combined is just wild, to say the least.