Whenever someone throws that sort of number around for “manufacturing”, it’s an indicator they’re trying to impress with overly broad claims. Manufacturing is extremely heterogenous and you’ll find a surprising mix of old and new equipment, processes, controls, and production volumes within a single factory, let alone a sector that ranges from making tortillas to space satellites as “manufacturing.”

The tremendous flexibility of human beings is often a better solution so far in material handling, material movement, some assembly work, cumulative judgement and skills (that’s the area that gets automated the most, not carrying a component a few feet) and sometimes quality control by inspection (also rapidly phasing out since people get bored and half blind at this quickly.)

It’s rapidly narrowing what people have to do with better robots, sensors, image processing and sensor data processing like temperature changes, lower cost networked cameras, wireless communication on the factory floor between devices (physical connections were maddening and frequently damaged), and costs have dropped precipitously.

When a robot was a quarter million dollars and partially replaced a $30,000/yr human and that for perhaps 5–8 years (machines wear out as well as obsolesce), people were the easy choice and in many countries you could hire 4–8 people for the cost of an American. When robots cost about 1 year’s wage for an American, that becomes a very fast decision and makes having 8 inefficient workers a 20 hour flight away/2 month container ship trip also look very wasteful indeed.

So 75% probably not for almost any factory now, over the next 10 years with the progress made since the 1970’s or 1870’s or 1770’s (when factory automation began in Northern England’s textile mills), far more can be automated and at a cost-recoverable rate.