Yep! I've actually even ridden bicycles before! My hips have never been secured to an upright bike. Every time I've tried to press harder on the pedals than my body weight, my hips have come off the seat. The force my legs have applied to the pedals has lifted my body into the air, against the force of gravity. I've been able to introduce a little more force on the pedals, with my arms pulling my body downward toward the handlebars, but not by much.

You're completely forgetting the fact that you're also pulling up with your "rear" foot as you're pedalling. Moreover, pedalling is not "push down repeat on other leg", but it's a circular motion where you're able to transfer power all through the cycle.

The maximum force you're able to put to pedals is irrelevant, because so much of the power you output depends on the cadence. If you're pushing your maximum force on the pedals, it already means you've lost the momentum and your power output is shit. The force has a small effect on sprints though.

Anyways, if the force was a major factor to prioritize, you'd see a lot more pro cyclists being swedish giants, but in reality most are on the shorter side. The benefits from lower weight and less drag from big body are far more important factors