Possibly not able to carry enough chemical fuel to lift the fuel into space and return and do a controlled landing without refueling? That seems more plausible.

Fuel is heavy, and most of it is spent on... lifting fuel.

With a modest increase in Earth's gravity, none of the rockets we have ever built would have been able to put even a small payload into even low earth orbit. Even a Saturn V wouldn't be able to launch Sputnik. Increase gravity a little more and no chemical rocket we could feasibly construct given known materials and methods would be able to do the job.

It's not about the amount of thrust. It's about being able to carry enough fuel to sustain that thrust long enough, without the weight of the fuel making the rocket too heavy to lift high enough to reach orbit.

You can't escape the rocket equation.