>>13360670>>13360676>With conventional rockets you are limited to about 2 Earth masses
Yes but that's just with conventional rockets, if we lived on a planet with more that that and really wanted to leave it we would eventually come up with some way to do it, be it NTR, Orion, launch loop or some fancy fusion tech.
You are looking at this from wrong perspective using our modern technology.
Earth has been around for 4.6 billion years, our civilization is just around for a few thousands, imagine what we'll be capable of in double of that time and yet that'll still be nothing compared to time we have left on Earth.
Gravity well is not some hard limit after which you can't leave the planet, it's just a delay, the higher the espace velocity, the longer it takes to leave and colonize local solar system but with progress of technology it's inevitable that intelligent specie will be able to leave it's gravity well, no matter whether it lives on Mars like planet or Gas giant type, there is simply too much time available for inteligent life for it not to happen barring any doomsday cosmic/civilizational event.