@Emilia42
I have also been using IB for several years and my experience has been more or less like yours. I have certainly never needed to use all three of my penalty free cancellations in the space of a year.
However, Like @Yves561 , I have noticed a real difference lately. In the space of a week, I had to call CS three times to get them to cancel an IB (third party booking, guests expecting to quarantine at my shared house even though the listing says this is not possible and guest refusing to tell me anything about himself or read the listing/house rules). There is a shift.
The Airbnb rep who dealt with the last cancellation told me it was because it's holiday season and people are 'panic booking', but I never noticed this before during holiday season. Perhaps it's a combination of that and COVID. Time will tell.
As for the pre-booking questions, those have always been problematic. I would say around 50% or more of IB guests tell me they never saw them. I still haven't figured out what that is about because I've had very good, communicative guests who said they never saw the questions either...