Let’s say I’m hiring you to build me some cabinets, but rather than paying you I will insist that you build the cabinets using precision laser cutters instead of saws, because precision laser cutters work so well.
Even though nobody has any laser cutters yet, and nobody could afford them anyhow, I will only pay you if you use laser cutters. Never mind the foundation that’s cracking beneath your feet, that’s not your concern. We have foundation experts for that, and they assure us that it can be fixed for a third of a penny or so.
The timing of my payment to you will depend on how some crazy people who hate cabinet makers feel about you getting paid. If they yell too loud I just might decide not to pay you at all, or I might decide to take the money and use it for a new garage door opener or garbage disposal instead.
In any event, you must build my cabinets, because you are a cabinet maker.