The ST is not very toyetic, it has no world building and the supporting media tie-ins are poor (that resistance show and the comics where’s the video games??). It just can’t capture the imagination of this generation like the PT. I was there as a kid in those PT times and it was huuuuuuge. Kids didn’t think they sucked only the the OT kids did (it wasn’t until I was much older that I found out that people didn’t like them). Social media nowadays has made it very clear that the ST was awful, even Khev and Jye cannot hold back the tide of online ST hate material that is available for this media savvy generation to see.
This doesn’t even factor in it has sooo much competition now the likes of which the PT never had. The MCU is a juggernaut and kids think it’s cool. It is the Star Wars of this generation. Plus kids have access to so much on demand media / content that they never dwell on a series for more than five minutes before moving on. The ST might have a small cult following in 20 years time but it’s not going to be like the PT today.
Plus, if you are looking at things from a purely visual/coolness point of view (as most kids do), there is nothing significantly "new" in the ST. Everything is mostly just a rebrand or recolour of things we saw in the OT. Kids aren't necessarily going to want a toy of something they've seen before.
Look at the designs of the Naboo Starfighters, Podracers, Naboo Royal Starships, Gungans, Darth Maul, Destroyer Droids, Battle Droids, Droid Starfighters, Trade Federation Ships, the Jedi Starfighters (both iterations), Republic Gunships, the Clone Troopers, Count Dooku, Dooku's Solar Ship, Kaminoans, Republic Venator Star Destroyers, Spider Droids, ARC 170 Starfighters, General Grievous, countless new Jedi Knights, I could go on and on.
That's without touching on the designs of all the new planets that add to the world building; Coruscant, Naboo, Geonosis, Kamino, Utapau, Kashyyyk, Mustafar, etc.
This is all before you even consider The Clone Wars and Rebels.
It all inspires the imagination just like the OT did.
Everything here and more from the PT/TCW/Rebels is new yet appears alongside and compliments things that we know from the OT. It doesn't rely on the OT as the ST does.
One thing that the ST did try and do in terms of originality was some new races and species. However, it did so whilst completely omitting and removing key races and species established in the PT and OT. The PT and TCW/Rebels all introduce new races/species whilst still including races/species from the OT such as the Sand People, Twi'leks, Rodians, Bith, Wookies etc., which makes the PT feel like a connected part of the Star Wars story with the OT. Whereas in the instances where the ST does introduce a new race, it looks like something from Men In Black and a little uninspiring, and there are no Sand People, Twi'leks, Rodians, Bith, Wookies (except Chewbacca) etc. to be seen. It automatically makes it feel like a universe completely removed from the Star Wars story, despite all the ships and soldiers looking exactly the same as the OT.