[prostoalex]

It seems that if you have a 100% working technology, you are better off filing for patents and licensing the tech to a large incumbent.

The need for venture financing arises when you're anywhere below 100% reliability, and are temporarily in this "fake it 'til you make it" category where the company has to rely on regular doses of cash infusions without much to show for (potentially) years. The problem with that approach is that for some the "make it" never quite materializes.