There are already pipelines through Saudi Arabia (
https://openinframap.org/#5.92/24.147/48.604/A,B,L,O ) but presumably there isn't not nearly enough capacity.
I imagine in addition to how long it might take to build a pipeline to Oman, probably Oman doesn't currently have enough port capacity and that might also take a while.
Edit: In fact, there is already a pipeline from the UAE to Oman, https://en.wikipedia.org/wiki/Habshan%E2%80%93Fujairah_oil_p..., precisely for the purpose to avoid the Strait of Hormuz. It took 6 years from design completion to construction finish. It has a capacity of 1.5 million barrels a day, about half an oil tanker.