“I'm assuming you got the basics right, so you do have a product market fit proven by having paying customers who are happy with your product.” Thats a huge as

“I'm assuming you got the basics right, so you do have a product market fit proven by having paying customers who are happy with your product.” Thats a huge assumption IMO. 99% of people never even reach this point. It depends on a lot of domain knowledge, a market, differentiation from competitors and luck too. Marketing is important, no doubt but mo amount of marketing can overcome a product nobody has the urgency to buy