If you are putting all energy and time to building your own thing and don't have conviction that you can beat 9% ROI of index funds, you should quit working on your own thing.
what if you haven't put enough money into the business to give it a fair chance at scaling?
if it's not clear that putting more money into business will provide more than 9% ROI of index funds, you should quit. otherwise you put more money in and keep grinding
Looks like he wants to be convinced that it is a good move to spend a lot of money in marketing. Maybe it is. Probably it is not.