Its the same with film and anime ,probably also aplies to comics and books Everyone remembers a few good titles from the ‘old times’ ( and the old times depend on the person complaining ) and comapres it to every modern production convieniently forgeting about the garbage and medicore stuff that was put at that time.

And then there is the case of some genres falling put of favor. Whetewer we are talking about western in film or RTS in computer games . That actually is pretty reasonable complain since the way it usualy goes we have a massive oversupply of certain genres followed by a drought because as it turns out there is a limit to how much harem school anime horny teenagers and middle aged corporate workers will watch per year.