Since when has this fear of a "man's dream" started to become so commonplace? Did new generations become really this gay? Or it has to do with how women got into this genre too?
It's honestly weird how I keep seeing this bitxing about harems everywhere since some time ago.
Ofc only the 1 man X many women type of harem, strangely the reverse harems or the polyamory ones where everyone does everyone are booming and it seems their stories are always peak.
It's like slasher films and ghost stories. Harems have been done SO often that people are just straight up tired of them. It's no longer wish fulfillment because people can pick just about any harem series they want and stick with that. Or y'know, just use the internet to look up actual harem hentai and other smut.
Harems have been done to death, or more specifically the "typical" way of doing them. Basic, generic personality types and body shapes (tsundere with a flat chest/modest figure, shy busty girl, athletic tomboy, cheeky mischief-maker, etc etc) with predictable one-note plot developments. Not to mention that most of the time the "winner" is obvious from the outset.
Which in itself is also a part of the problem: "harem" anime/manga
almost never end with an actual harem. 90% of the time it's narrowed down to one girl at the end, with the other girls suffering various levels of heartbreak as a result. So if you're not a fan of the winner or liked another girl more? You just wasted your time and investment.
I can't talk about reverse harems, but
actual harem manga are getting more popular because it means "everyone wins." The girls all get to be with the man they love, the fans of those characters get to see them happy, and harem fans get to see the ACTUAL fantasy of having multiple women loving the MC without all the competitive fuss of typical harem manga. The fact it bucks the "one man, one woman" expectation of modern society is just a footnote.
TLDR: Harems are overdone and now most people only enjoy them if they actually have something unique to offer.