That is what I am trying to explain, now for the second time.
Let's say you have a magic factory that turns rocks into advanced circuits, for simplicity's sake, after 16 seconds. You need 3 advanced circuits for one chemical science pack. If you only have one circuit factory, you need to wait 3 * 16 seconds to produce three circuits. If you have three circuit factories that can grab from the conveyor belt at the same time, they can start work at the same time. Then the amount of time it takes to produce 3 advanced circuits, starting with all three factories completely inactive, is 16 seconds, assuming you have 3 rocks ready for consumption.
The time it takes to produce a chemical pack, in turn, is the time it takes to produce 3 circuits, plus 24 seconds to turn the finished circuits into a science pack. It stands to reason that if you can produce 3 circuits faster in parallel than sequentially, you can also produce chemical science packs faster sequentially.
> Suppose instead of producing science packs, your factory produces colored cars. A customer can come along, press a button to request a car of a given color, and the factory gives it to them after a certain time. You want to answer customer requests as quickly as possible, so you always have ready black, white, and red cars, which are 99% of the requests, and your factory continuously produces cars in a red-green-blue pattern, at a rate 1 car per hour. Unfortunately your manufacturing process is such that the color must be set very easy in the pipeline and this changes the entire rest of the production sequence. If a customer comes along and presses a button, how long do they need to wait until they can get their car? That measurement is the latency of the system.
Again, I understand this, so let me phrase it in a way that fits in your analogy. Creating a car is a complex operation that requires many different pieces to be created. I'm not a car mechanic, so I'm just guessing, but at a minimum you have the chassis, engine, tires, and the panels.
If you can manufacture the chassis, engine, tires, and panels simultaneously, it will decrease the total latency of producing one unit (a car). I'm not talking about producing different cars in parallel. Of course that won't decrease latency to produce a single car. I'm saying you parallelize the components of the car. The time it takes to produce the car, assuming every component can be manufactured independently, is the maximum amount of time it takes across the components, plus the time it takes to assemble them once they've been completed. So if the engine takes the longest, you can produce a car in the amount of time it takes to produce a engine, plus some constant.
Before, the amount of time is chassis + engine + tires + panels + assembly. Now, the time is engine + assembly, because the chassis, tires, and panels are already done by the time the engine is ready.