That is pretty much all there is: If earth was more massive, the chemical rockets we've been producing wouldn't have enough thrust-to-weight ratio to reach orbital velocity (about 25k km/h). We would have to load the rockets with so much fuel to break free of gravity that they would be too heavy to lift themselves.

This is all assuming yields and fuels we have now. If we lived on a more massive earth and we were trying to escape its gravity, I'm sure we'd be using more exotic and dangerous fuels (like all those fun fluorine and boron fuels Dr. Clark mentions in Ignition![0]) to do the job. We just happened to have the capability in the middle of the century to use a fuel we were already making (refined petroleum) for jet engines.

[0] https://www.amazon.com/Ignition-Informal-Propellants-Univers...

You can get it on Kindle:

https://www.amazon.com/dp/B076838QS2

Well worth the money. I don't think I'd pay the $90+ people are asking for a hardcover version...

This is probably the best book on how the professionals had fun building rockets back in the day. It's a gread read, and full of useful practical chemical engineering advice and cautionary tales. You might find PDFs, but you can also buy it here: https://www.amazon.com/Ignition-Informal-Propellants-Univers...

Finally back in print after 40 years!

https://www.amazon.com/Ignition-Informal-Propellants-Univers...