For me, the biggest roadblock is actually owning ETH. You may thing that's trivial, but I'm not so sure. Apparently 10m people in the world own SOME form of crypto[1] - so, there's your upper bound on number of users. For a mass-market product, 10m is really not that much .... you don't just need "traction", you need traction that is so significant that it pushes up the entire crypto market! I'm skeptical, but who knows? Good luck.
[1] https://www.quora.com/How-many-people-own-at-least-some-cryp...