2PC requires two network round trips and a global synchronization point. Plus it has the blocking problem and the cloggage problem described in the blog post. The first read of OLLP is before the first lock is acquired, so it doesn't result in any additional cloggage, and definitely no blocking problem.

There's two round trips if the read is foreign as it needs to be done twice.

But my point was supposed to be positive. Doing something like 2PC or something like it only when it's needed is a huge improvement in the "pay for what you use" vein.