Below is a link to a thorough and houghtful exposition of these pipelines. Basically the article says that they were already in use before the war so there's only so much that can be pumped through them. And they can't be fully utilized because the terminus at the Yanbu port can only load, at most, 4.5 million bpd. At most. And about 2 million bpd of that capacity is already being utilized by a Saudi refinery on the Red Sea. In addition, those pipelines can only transport crude oil. A large percentage of the tankers passing through the straits carry refined distillates such as diesel or jet fuel. Hormuz Bypass Infrastructure Was Sized for a Short Disruption. This Is Not That. For four decades, Gulf oil producers made a calculated infrastructure bet: any closure of the Strait of Hormuz would be temporary and that partial bypass capacity—enough to bleed off pressure for days or weeks—was sufficient insurance. The narrow waterway normally carries roughly 20 million barrels per day of petroleum liquids, approximately one-fifth of global consumption, according to the U.S. Energy Information Administration. There currently exist two overland pipelines built to bypass the strait, which can, at best, move 4 to 5 million barrels per day to export terminals. https://www.enr.com/articles/62677-hormuz-bypass-infrastructure-was-sized-for-a-short-disruption-this-is-not-that