Venture capitals are no longer giving investments for just an idea. You have to prove that you put your skin in the game and have made your first product steps.
Initial customer research is hardly enough to risk with the whole project budget. Test idea with MVP and get valuable feedback - that’s important.
There is no sense to make a fully working product until you’re sure that all the features are technically possible. Test Scalability, 3rd party integrations and algorithm realization first.