There are, indeed, huge problems with manufacturing as we do it now.

Planned obsolescence is symptom of it.

In other words, in the beginning you need to make a toaster for everyone in the world.
A big factory making toasters as efficiently as possible is the way.

But, after you made a toaster for everyone,... what do you do?

Big factories do not scale back.
And, as you have seen in your game, big factories have huge problems in scaling up

So, big factories have a minimum and a maximum they can produce.
And your demand HAS TO fall in between those two numbers.
There is nothing you can do if everyone suddenly wants twice as much toilet paper on hand.

In the future i see a lot of machinery that will live in people's garages, and when someone needs a new part, they just call up Joe, or Bob, and say, "make me one of these please."

And it just sits idle with almost no overhead until the next part is needed.
This situation scales from zero to as many as there are people to make them.