Marketing POV: Do you agree?

In today's marketing, I have seen that you must first validate your idea through the crowd before building it.

I don't debate that!

It's true!

But I feel that, that alone is not only true.
When it comes down to an idea, you can choose an idea without having it to be validated by the crowd. Also, YOU DON'T JUST CHOOSE ANY DUMB IDEA, OF COURSE, you chose it because it could have traction.
But, of course, if the idea has no execution, the idea becomes worthless.

Why do I believe this to be true?
Because nowadays we have evolved so much (technologically) that it's easier to interact around the world.
Because back then, there was no communities or platforms where you could validate an idea.

And as I'm writing this, it reminds me of the show "AGT" Lindsey Stirling.
Not everyone (and probably most of them) will NOT be in accordance with your talent/idea until you work on it hard enough that now everyone wants it.