[ultraman zoffy]

David Vonner's podcast from last year addresses most of the issues around this argument, so I definitely recommend listening to it if you haven't yet:
Marvelicious Toys - The Marvel Universe Toy & Collectibles Podcast

It's such a good discussion that I have it saved on my phone and listen to it on long drives. lol

To me, it seems to just boil down to over saturation, lower quality, bad toy lineups, and parents willing to buy a mobile phone or tablet for their kids instead of an entire action figure line that you could probably get for the same price. At family parties, I notice what my nephews and nieces are playing with, and it always seems to be the latest craze as opposed to action figures: kendamas, those weird rubber band kits, junk like that. For Christmas, I actually got more toys than they did from our secret santa exchange! lol
Another thing I think doesn't get brought up often is that in this day and age, it just might be a shift of parents nowadays being scared to give their kids toys associated with on screen violence. A lot of them are probably afraid of raising the next active shooter, and so maybe they're just staying away from what they perceive influence that sort of thing (which is b.s., btw).