I think the whole thing between both platform is drastically different for each property and largely unexplainable ;)
I have 4 STRs in the Pigeon Forge area market. We have one in the PF city limits, two just outside the city limits (Sevierville) and the 4th in Wears Valley.
When we started several years ago, we were 80/20 across the first 3 cabins VRBO to AirBnb. We much preferred dealing with VRBO for sure. When we bought the Wears Valley cabin, the previous owners told us they only get bookings on AirBnb. When we setup our listing, sure as anything we couldn't get a VRBO booking on that property for 6 months. Several phone calls with VRBO basically went like this: "Well you need to get more bookings to rank higher and be shown in the listings" my resposne "ok but if you don't show me in the listings how am I going to get more bookings?" and we would go back and forth.
We finally got some VRBO bookings on that property after we let several friends stay there very cheap just to get some reviews and bookings on the VRBO side. It took major effort to get VRBO bookings on that property for some reason. VRBO has never been the dominate platform for this particular cabin.
Things have changed in the last 18 months rather drastically across all my properties. VRBO bookings have gone down overall across the board and whereas in times past it was 80/20 VRBO, now only one property has more VRBO bookings than AirBnb and it is nowhere near an 80/20, it is closer to 55/45.
Speaking with my VRBO account manager, they acknowledged that HomeAway has not been advertising in my market like they need to be and AirBnb has dominated in that market and they recognize they need to fix that.
The other thing that has changed in my situation is that I have been focused on growing direct bookings through my website. I just checked and for 2025 my direct bookings represent the following percentage of bookings across my 4 cabins: 5%, 18%, 22%, and 25%. I was extremely happy to realize those numbers after my efforts. It does mean less available time open on VRBO and that could play into the shift as well with lower VRBO bookings.
One last thought, on the cabin that is doing 5% direct bookings, that is in a cabin resort neighborhood. My buddy owns the cabin rest next to me. Same layout, both are indoor pool cabins, same sq footage. Slightly different on some amenities but both are loaded. My cabin has 45% of its bookings from VRBO and 45% of its bookings from AirBnb. Again right next door to mine and he can't get a VRBO booking to save his life. He gets zero VRBO bookings. He used to but now nothing. It really makes no sense at all. He has had calls with his account manager and he gets the same conversation I used to get on the other property.