I'm not a "founder" in any real sense of the word but my feeling is that it depends on what market you're targeting. If your goal is to become a billion dollar unicorn, then yeah it's going to be tough to beat free because you're going to need a huge number of users. On the other hand if you're OK with building a small sustainable business to support yourself, family and maybe a small number of employees then I think it's possible to target niche markets of people who are willing to pay for a high quality, well designed product that does exactly what they need.

For now this is just my working hypothesis, I'm still far from being in a position to test it.