You are totally right- it takes decades.

But lets face it - in a company- there are two or three people doing the game-design, the others usually get not even a chance to contribute.

They are put into a silo, connected to a part of the pipeline and start crunching until the ilusion wears off. Even if you get a chance to realize a idea- in a modern title, the fear of risk, sees to any new concept that it is marginalized.

So even if it takes years, i think by now, its far more realistic to produce a title as a indy dev or open source dev by now.

Had I the heaven's embroidered cloths,

Enwrought with golden and silver light,

The blue and the dim and the dark cloths

Of night and light and the half-light;

I would spread the cloths under your feet:

But I, being poor, have only my dreams;

I have spread my dreams under your feet;

Tread softly because you tread on my dreams.