I posited a similar point to a former colleague (mine was more about eventual market dominance due to excellent UI+UX), and he came back with Craigslist as a perfect example of a product that gained a massive user base well into an era where its UI felt very outdated. A few years after this exchange, I feel more like I was right about my point: FB Marketplace has almost completely taken over as far as a classified product marketplace, but the point still stands that Craigslist was able to do a ton with very lackluster UI+UX