Is a megaproject like this a good idea considering that there could (possibly) be innovations in the sector? What if scientists find a way to reduce the panel size by 30% in the future?
At some point you have to stop worrying about the future and recognize the benefits you can get today with the resources and technology you have avaliable to you.
They were building the pyramids thousands of years back. And we continue to tall buildings even now.
Next after that, is that the construction will take place over decades. So it should reasonably be assumed they'll take advantage of some improvements along the way.
each barrel that they don't burn is one they can sell instead, and this is a situation that makes economic sense for them now, regardless of future tech improvements.