I’ve been reading these threads since 2019 when I bought my first BAC, and even then, it was not uncommon for people to have 4 or 5 calendars. I even remember one poster, several years ago, who left it really late to buy a calendar, and then came on the BAC to complain that people on the thread had bought multiple calendars while she didn’t have any!
If you are going back further than 2019, then I expect that people where buying fewer simply because there were fewer available. Cult Beauty and F&M for example, didn’t launch in 2019 I believe. I also don’t think that there was HN or any fragrance calendars back then.
It’s very strange that you seem to have an issue with how many calendars people buy and what they do with the items. Why on earth does it matter? Personally, I didn’t buy any beauty products at all between January and August this year. Not even a shampoo or shower gel. This time of year, I like to stock up on things.