Redfin didn't exactly do anything interesting or unique. It was literally yet another real estate app/website. It's not surprising.
To be fair, Redfin is a technology focused MLS member and agency, not just a listings aggregation app. You're entitled to your opinion if you don't think that is interesting or unique, but their offering is far more than just a website and app. Interesting data on their agent stats and comp here: https://www.redfin.com/blog/2018/01/how-much-do-redfin-agent...
Also there is no MLS, there are a lot of them.