The CPTO seat follows from cheap building
Product decided what to build, and engineering built it. The handoff between them was expensive enough that you wanted a senior person owning each side. When building was slow, that was the efficient way to split the work, and the wall between product and engineering was there for a good reason.
Building got cheap, and the handoff mostly went with it. One capable person can now hold the product call and get close enough to the build to make it real. Once that's true, 2 senior leaders coordinating across a boundary turns into overhead. Every decision still has to cross from one side to the other, and the crossing no longer buys you much.
The CPTO is one person running both product and engineering. Nobody sat down and decided that role should exist. The wall stopped making sense, and the title is the name we're putting on the rubble. One person owning the line from what's worth building through to whether it landed is a CPTO, whether or not you use the title.
The deeper collapse is between strategy and operations. Direction set quarterly and reviewed monthly can't steer something running at agent speed. By the time the review comes round, the work has changed. The strategic call and the operational call are now the same call, made with the numbers in front of you. Split it across 2 executives and you've put the handoff back at the level where it costs the most.
The pay follows the work. A CPTO seat that pays more than either seat it replaced is one person doing what recently took 2. The seat asks for a technical depth the product role never used to require, and the person in it carries the read afterwards. Companies are paying for a real consolidation.
The CPTO gets discussed like a fashion, and fashions reverse. Cheap building dissolved the boundary between product and engineering, and if anything that effect is getting stronger, so I expect this seat to stay.
The question for a company is whether its product leadership is still built around a wall the technology already removed. One way to check is to take a recent launch and trace it from the product call to the read on whether it landed. Count how many senior leaders it passed between on the way.