Statement: you can’t have good quality, fast and cheap at the same time.

Only:
Good and fast, not cheap.
Good and cheap, not fast.
Cheap and fast, not good.

This is a common misunderstanding: it can be all 3.

Why?

The better your processes, the less waste you have.
The less waste you have, the faster you can produce.
The less waste you have, the higher quality you can produce.
The less waste you have, the less resources you need.

So this then leads to higher value per unit of cost/time.

If you want to improve, focus on value added activities / cost.
If you focus on cost, it invariably leads to worse quality by higher cost.

This is the reason why so many cost cutting operations go wrong…