Well,. wood is realistic. The challenge is how long is this beam and how do you want to piece it together. If it's less than 16 ft. long you can probably wrap it with no vertical joints. There would be horizontal joints as the beam looks taller than you can reasonably buy lumber.

This article suggests using wood flooring -- which eliminates the need for finishing since it's pre-finished -- to clad the beam: Wrapping a Drywall Ceiling Beam With Hardwood Flooring

Wikihow How to Wrap Beams

I'd have it faux painted. You'd never know it wasn't one piece, especially from that height.

Good idea!

"I'd have it faux painted."

This video (https://www.youtube.com/watch?v=CIZZfzCVmLo) shows how to do it but doing it on a small piece of wood set on a table would be a lot easier than doing it on a large beam high above the floor!

The flooring idea is totally doable! I’ll keep you posted when it’s done.