Yes, there was a specific risk with ST merchandise, but there was a point in time where the ST was dragging everything Star Wars down with it to an extent.
Doesn’t mean OT specific items weren’t selling, but it’s important to remember that diehard collectors like us exist in a bubble.
There are collectors who will happily buy collectibles and toys from the OT, PT, TCW, Rebels, games, comics, Legends, etc. to suit their tastes, but there aren’t enough of us to see the kind of profits these companies want to see.
There needs to be something big that’s marketable like a tent-pole film, event, tie-in, anniversary, new TV show, and the like to get the general population excited to mitigate risk and sell as much plastic as possible.
So there was a definite low point between the harsh TFA post honeymoon period and The Mandalorian’s rise to popularity that tarnished (relatively speaking) the marketability of the brand as a whole, especially in the eyes of the companies that made products for the movies that didn’t sell well.
Even though it’s only been a few years, it’s easy to forget how bleak the future of Star Wars as a whole looked before Disney+ and the revival of The Clone Wars, the premier of The Mandalorian, and the announcement of a whole slate of new shows.