100 years is not a long time. Compare a railroad now to a railroad we had 100 years after the invention of railroads. There are massive improvements still poss

100 years is not a long time. Compare a railroad now to a railroad we had 100 years after the invention of railroads. There are massive improvements still possible in the engine. Like the currently in design RISE engine. And other engines as well. And if you combined the technology you can get even further. We are not close to the end on any of this. See: https://www.youtube.com/watch?v=XkHKet7rp4o https://www.youtube.com/watch?v=XkHKet7rp4o There are various aero-dynamic concepts that have not yet been fully or even partially explored. Trust brace wings, blended wings or my personal favorite, Prantdl Wing. A Prantdl wing might allow you to remove the whole tail, another huge potential boost. You can even combine all these concepts potentially. I would guess we can get 40% more efficiency just based on those things.