VRBO has been around since 1995. My parents had their vacation condo listed on there for a long time. The reason you don't hear about them is that they weren't controversial with sharing out rooms and didn't invest in pretty design.

I really think they dropped the ball when Airbnb moved into the space

It depends a lot on the area you're visiting. VRBO has a much larger supply in certain areas, especially traditional resort type destinations like ski towns or beach towns.

Maybe it's geographic. I've used VRBO exclusively and never found a comparable option on Airbnb. VRBO fees to renters seem lower and you feel closer to the property owner with less glam or polish from the agent obscuring the realities of the property.

VRBO feels like craigslist, while airbnb feels like eBay to me.

VRBO basically is what people used before Airbnb. As a long time user of it I never really understood the Airbnb hype. I guess Airbnb penetrated markets due to hype and marketing which vrbo was unable to. But they are basically the same thing for end users.