Thanks @Huma0 for the tip!
I have now checked which categories I am in: Lake (good), Lakefront (pushing it slightly, but thanks!), Tiny homes (good), National Parks (surprise to me, but turns out to be correct! - have added more info about these in my ad, thanks Airbnb!) and Skiing (weeell, yes, but it is not exactly the biggest slope...).
However, I am not in the categories Beach and Golf, even if there are multiple beaches and golf courses just a few minutes' drive from my listing - definitely no further away than the national parks and skiing slopes. And I see that several houses very similar to mine, or in both the Tiny homes category, and the Cabin category, whilst I am only in the Tiny homes category. Tiny homes is not a well known thing in Europe, I think, so I should probably be in the Cabin category too, like many other equivalent listings.
So I contacted Customer Service, to ask if they could look into it. They replied with some standard message about how listings are ranked, and how I could boost my ranking. I replied that this was not an answer to my question, and I know very well how to boost my ranking. I was asking about Categories, not ranking in listings.
My case was then sent on to another representative, who told me CS have no influence over which categories a listing is put in. I mentioned the fact that Catherine Powell herself had made sure that a listing was in fact put into a category where it should already have been, by contacting "the Category Team". And could my case please be sent over to this "Category Team"? The CS representative replied that there is no Categories Team...
Which I found quite interesting.
Oh well, I've added more pictures and mentiones of the beaches and golf courses, and also mentioned "cabin", and will give it a few days, to see if I am actually added to these categories. Not that I think that it is that important for my bookings. But there really is no point in having categories, if they are to be used as reandomly as they appear to be, is there?
[Private conversation removed in line with the Community Center Guidelines]