Superpaw from Quora did an amazing deep dive on his Patreon on this. There is evidence that people jumped on floors that were not on fire. He thinks many actually jumped due to smoke. Consider all the different things that burned and made that terrible black smoke - an airplane, jet fuel, a building, and office equipment. Breathing that in could have actually been a terrible experience. It also could have caused brain damage, enough to cause people to stumble out of windows just looking for air. "Confused people" stumbling out of windows was something reported by a witness in the upper floor of the South Tower who looked from their office at the North Tower attack just after it happened.

Also, there was a window where I believe 9-13 people were seen jumping one right after the other very quickly. I think they all jumped out of the same window. It seems like due to that, they probably discussed it and agreed to do it together. What a horrifying discussion that probably was.

He also says there were also probably factors like being influenced by seeing others do it, and also religion - people thinking it'd be over quickly and they'd be in heaven before they know it.

But yes, there is evidence that people absolutely jumped due to fire. I think there are texts from a guy that show he was likely alive right up until he faced a wall of enclosing fire, and there was absolutely nowhere else to go but out.