In many cases, the prices are noticeably better, but the two big other reasons are location and a unique experience.
The last time I traveled, it was to Europe (I'm US-based), where I visited France, Germany, and Switzerland. The AirBnB we had in Provins, France was amazing—it was basically just a shed in a backyard (far enough away from the house that no sound reached there), but it was very well-appointed, and right outside the window were chickens, and we were encouraged to just go take freshly-laid eggs for our breakfast.
When we stayed in a guest room in a German village near the border with France (I'm afraid I've forgotten the exact location), the host couple invited us down for drinks in the evening—we're not big drinkers, so we didn't take much, but the selection was (at least to our American eyes) amazing, and the company was just lovely.
On the other hand, our AirBnB in Switzerland was almost as bad as some of the horror stories being told here. The host couple was disinterested almost to the point of hostility, and they left us a very bad review on AirBnB afterward, for reasons I can no longer recall, after pressuring us to give them a perfect review. Even if the pandemic had not stopped our travel after that, this experience was enough that we were seriously, seriously reconsidering using AirBnB ever again.
And that's the thing: when you're planning a vacation, one bad experience can so easily overwhelm all the good experiences—especially when it comes to having a safe, clean, reliable place to sleep at night.