This has also happened to me twice. In both cases, it was when we got a good price booking well in advance for a known-busy season, and the cancellation was last minute and left us totally screwed because there were no alternative accommodations available within our budget.

In both cases, Airbnb would only offer us a refund plus maybe like 10%. They would not make any effort to rebook us at an equivalent property.

My theory is that because Airbnb does not sufficiently penalize hosts for these sort of late cancellations, hosts are incentivized to cancel cheap bookings to get a more expensive booking on another platform if prices meaningfully increase.