I have rented 1 week on Koala. Thanksgiving week in a 3 BR at Wyndham Bonnet Creek. I placed about 7 ads, I cancelled ads, as no nibbles were found and I was coming up against the cancellation window. I currently have 3 ads in place (March Break - Hawaii, July 4th - Hilton Head, October - WDW 50th Anniversary).
So I think Koala may still lack some traffic, as people are just finding them, but it will be increasing. So if you have the right item at the right place at the right price, it will get picked up if someone wants that week. Travel is still down, especially for non-timeshare folks.
But it is only your time but not money to place an ad. I am being selective, putting quality weeks and locations at desirable times, in their pool. Again since it only costs commission if you rent vs placing an ad, I think it is a viable alternative, given the rental market is a bit shaky right now. So I think patience is required.