In my opinion, it is, because it can show investors that the team is ready to bring huge results and has future plans.
As an example - KickCity, event platform where each user is rewarded for event promotion. You can try it today. More information you can find here https://medium.com/@kickcity_io/kickcity-public-beta-5aa66fafc5c7
I am also sure that a project without a ready and useful product has no real prospects for successful development in the future. It is unlikely that many investors are willing to risk large sums of money, choosing a project without a finished product. Therefore, the product is extremely important for successful work, but other selection criteria must be taken into account.