I'm sure some hotels only show you the resort fee after you've booked but I'm not only talking about that: I consider them a scam in concept because it is a fee

I'm sure some hotels only show you the resort fee after you've booked but I'm not only talking about that: I consider them a scam in concept because it is a fee that hotels allege covers specific things (parking, wifi, pool access & other amenities) but the fee is not optional, it cannot be avoided even if you won't be parking or using the pool. But I also consider them a scam in practice because hotels & OTAs go to such lengths to hide them during the search process. By advertising a rate that doesn't include these fees they are advertising a rate that simply doesn't exist. It is (sadly) the default practice in the states to advertise the price of basically everything pre-tax, so at a minimum consumers here expect for tax to be added (though folks new to booking a hotel probably don't know about occupancy taxes). But for a hotel or OTA to advertise 2 different hotels, one with a $30 / night resort fee, as both being $199 / night is also a scam. Hotels do this for banquet & convention services as well. Everything is "plus plus", meaning plus tax plus a service fee %, usually 20% in my experience. Your $10k banquet hall rental is really $13k if the tax on it is 10%.